MUSEUMS & GALLERIESCOMMISSION

THE CONSERVATION UNIT

Museum Collections in Industrial BuildingsA selection and adaptation guide

BILL BORDASS

MAY CASSAR (Editor)

MUSEUMS & GALLERIESCOMMISSION

THE CONSERVATION UNIT

Museum Collectionsin

Industrial Buildings

A selection and adaptation guide

Bill Bordass

May Cassar (Editor)

Limitation of Liability

© Museums & Galleries Commission 1996First published 1996ISBN 0 948630 38 8Designed and typeset by TechsetComposition Limited, Salisbury and printedin the UK by Bigwood and Staple,Bridgwater, Somerset

Registered Charity No. 295943

The advice and information in thispublication is given in good faith and isdeemed to be an appropriate analysis of thesubjects under discussion. It does nothowever constitute precise instructions toenable a detailed solution to be carried out.The Museums & Galleries Commissionstrongly recommends that advice isobtained from the appropriate specialists.

Cover illustration: The Museum BuildingCommitteeThanks to Tim Padfield, Nationalmuseet,Copenhagen, for the cover cartoon.

While best read from beginning to end, this Guide is based on a series ofrelatively self-contained sections, most of which occupy a two-pagespread.

ForewordThe primary aim of this publication is to improve communicationamong all those involved in the design and adaptation of premiseshousing collections. It is intended to empower the end-user, informthe developer and help the building designer avoid serious problemswhich are often quite elementary technically but which arefrequently overlooked or not properly discussed at the appropriatetime during the development of a project.

The Conservation Unit of the Museums & Galleries Commission hasproduced this Guide in response to a trend among museums to seekaccommodation for reserve collections away from their main site.Traditional stores are developing as resource or support centres,thus providing museums with the opportunity to improve accessi-bility and care for their collections. While this Guide has been writ-ten primarily to advise museums on the procurement of storagebuildings, its recommendations, particularly its approach to envir-onmental control, can be applied more widely to other buildingprojects.

While environmental control was the spur for the development ofthis Guide, other important issues were soon recognised and in-cluded. Safe access by visitors and staff is a key consideration. Anoff-site facility will not meet a museum's expectations if staff feel un-easy about working - possibly alone - with collections on a remotesite. Equally important, visitors must not be put off by bad or messyneighbours if a new facility is located on an industrial site. Other im-portant management considerations are whether a new facility canbe operated from the main museum site and whether collection-careconcerns over the transport of objects between distant locations canbe addressed satisfactorily.

This Guide aims to encourage museums to carry out cost/benefitstudies of the re-housing options before them and thus enables themto prioritise the use of available resources, given the wide range ofissues that a museum needs to consider when developing a new fa-cility: access, collection care, management, security, health andsafety issues.

This Guide deals mainly with spatial planning and environmentalmanagement issues. It focuses on the selection, design and adapta-tion of industrial buildings in order to achieve appropriate internalenvironmental conditions at an affordable price and it links spacerequirements to collection need. But the Guide is also intentionallyshort and succinct, and therefore it cannot hope to cover in detailthose aspects where specialist advice may be required, namelybuilding fabric conservation and repair, maintenance, security andfire protection.

Neither does the Guide suggest that procuring cost-effective storagespace is sufficient to achieve low running costs. Clearly, the way inwhich the energy consumption is monitored and managed will af-fect this, so the operating practices of the staff, including training,need to be considered.

While this Guide is both strategic and practical in its content, it cannever replace the value of going out and looking at examples of mu-seum collections in industrial buildings, when a museum is contem-plating such a move. This advice also applies to the buildingdesigner. When the whole project team is looking at the same thing,there is less of a chance of confusion and misunderstandings, lead-ing to costly mistakes which may be difficult to rectify later.

May Cassar February 1996

Acknowledgements

This Guide was originated by the Museums & Galleries Commissionand William Bordass Associates was commissioned to carry it out.Bill Bordass and Joanna and Peter Eley undertook the study anddrafted this Guide. SVM Partnership Ltd undertook some of the casestudy investigations and related computer modelling. Financial as-sistance was provided by the Department of Trade and Industryunder the Energy Design Advice Scheme (EDAS).

We would also like to thank BRECSU and the Department of theEnvironments Best Practice programme for their helpful commentson energy efficiency.

The assistance of all those who have given us their views, dis-cussed their plans, shown us round their stores, and commentedon drafts is gratefully acknowledged.

G

The Building's Performance as aProtective Enclosure 13

General RequirementsA Sound ShellLow Air InfiltrationGood InsulationLimiting Heat GainsHigh Thermal Capacity

HImproving the Thermal Performance ofthe Building Shell 14

What is a U-value?Upgrading Insulation and AirtightnessInsulation: Points to WatchRelationships Between Temperature, Rela-tive Humidity and Moisture

JBuffer Zones, Airlocks andContainers 16

Problems with Poor External WallsPlanning Buffer ZonesAppropriate ContainersDoors for Goods, Vehicles and PeopleCase Studies of Use of Buffer Zones

KBuilding Services 1:Heating and Ventilation 18

Heating EquipmentFire and Flood RisksVentilation Systems

LBuilding Services 2:Control of Internal Conditions 20

Control DevicesAir ConditioningHumidity Control

MCase Study 21

Assessment and Upgrading of IndustrialUnits

NChecklists 22

Organisational ChecklistTechnical ChecklistStorage ChecklistMove-in and Occupancy Checklist

PReferences 23

In the text, references are identified in squarebrackets, for example [4].

QSources of Advice and OtherInformation 24

ContentsForeword

Acknowledgements

Introduction 1

AInitial Decisions 2

A Good Storage BuildingThe TeamThe ProcessInitial DecisionsThe SearchAn Outline BriefSome Issues to be Considered

BTypical Characteristics of IndustrialBuildings 4

Properties of Typical BuildingsHidden HazardsStructural Systems

CEvaluating Sites and Buildings 6

Site LocationSite CoverageBuilding Form and TypeSpatial ConfigurationsStructural Checklist

DStorage Planning and Systems 8

Storage ClassificationsStorage PlanningPoints to WatchRelationship DiagramsPlanning Entrances and AislesDo Not Waste Vertical Space

EEnvironmental Control Requirementsand Principles 10

Storage Conditions for ObjectsConsidering StandardsAre Variations Acceptable?Indoor Air QualityMoisture-Related DeteriorationThe Influence of the BuildingThe Role of Building ServicesEnvironmental Control Strategies

FNatural and Electric Lighting 12

LightingExposure to LightLight Sources and FittingsLight SwitchingDaylight and SunlightLighting of Mobile Racking

Introduction

'We have much more material in store than wecan ever display.'

'It is increasingly hard to justify the cost ofproper storage facilities unless public access isprovided.'

'The stores are far from adequate but it is hardenough to finance the necessary work to the mu-seum itself: can we get better, but low-cost,

space?'

'The lease is running out: we need a new storeurgently.'

• What do we really want?• What advice do we require?• What questions should we ask?

• What buildings are available?• What type is best for us?• What are the most important features?• Should we rent or buy?

• Can we proceed in stages?• What are the pitfalls and problems?• Do good prototypes exist?

• Can we control the environmenteffectively and economically?

• What are the options?• Do we need air-conditioning?• Can we afford it?

Purpose ©f This Guide

This Guide addresses many questions likethose above, both in general and with case-study illustrations. It is particularly aimedat:

• Museum curators and conservators.• Collection managers and administrators.• Funding bodies.• Architects, engineers and builders.

Building owners, developers, surveyors andestate agents will also find sections of inter-est, especially A, B, C, F, G & H.

The Guide's prime emphasis is on the mainstorage area - and, in particular, its inter-nal environment - and on assessing andmodifying part or all of an industrial build-ing (both old and new, large and small) andreviewing developers' package deals. Muchof the material is also relevant to museumstorage generally.

Many problems that occur in practice can betraced to differing perceptions by buildingand museum professionals. The Museums &Galleries Commission hopes that this Guidewill assist all those involved to share theirunderstanding of the issues and make betterdecisions.

Museum of London Eagle Wharf Road Resource Centre which houses theMuseum's reserve collection and to which visits for the public are organised.

Museum Storage in IndustrialBuildings

Housing collections Is of fundamental im-portance to the function and purpose of mu-seums [1]. However, stores are too often sec-ond-rate, having expanded incrementallyinto whatever cheap accommodation hap-pened to be available at the time [27]. Storageis now under pressure as requirements foraccess, security and study increase, and ac-cessible storage space in central museumbuildings is earmarked for conversion Intonew public facilities. The importance to pre-ventive conservation of good, well-managedstorage conditions is also better recognised[20.42].

Industrial buildings, particularly old ware-houses and newer industrial units, areincreasingly being considered and used formuseum storage. They promise low-costspace of suitable proportions and load-bear-ing capacity, and are particularly appropri-ate for collections including industrial andsocial history, architectural fragments andbulk archaeological finds. But industrialbuildings also harbour many potential pit-falls: in functionality, cost and performance,Many available buildings, both new andexisting, are unsuitable, poorly located ormay require more repair and alteration thanis initially apparent. Sometimes, even aftermuch money has been spent, the desiredresults may not be achieved.

In the past, storage has not had high priorityfor funds from local authorities, benefactors,or appeals, and seldom has there beenenough money for a new building. But donot set: your sights too low: good storage isvital, and the growing tendency for storesto become resource centres with publicaccess could well make storage more attrac-tive to funders.

This Is Not a Recipe Book

While this Guide attempts to raise issuesand to identify frequently occurring pro-blems and solutions, each museum andbuilding is unique and will need to workout its own questions and answers. Theteam (which includes client, buildingdesigners and advisers) must enquire intoeverything and learn from the specialistknowledge of all its members. While therewill always be constraints, if one findsdesigners blindly following the brief, or, onthe other hand, saying flatly that somethingthat appears desirable cannot be done, cli-ents should insist that options are carefullyexplored.

An integrated approach with clear thinking,specialist advice and good communicationsbetween members of a well-constructedteam is essential for there to be practical,economical and effective solutions. Whilethought and advice will cost time andmoney in the first place, the investment willbe well-rewarded and good, sound low-energy storage conditions can be achieved.

The Importance of the internalEnvironment

Internal environmental requirements, andespecially the control of moisture levels,can be particularly exacting, and there aredangers of both over- and under-specilica-tion. The implications are not always well-understood when a building is selected andcan lead to poor strategic decisions -atworst, the wrong building.

Plan the Move Carefully

Moving is always disruptive and time con-suming. It also has 'knock on effects, eg:items may need to be re-catalogued andnew uses accommodated in space released.If the whole process is not done carefullyand funded adequately, much effort may bewasted and items may even be damaged.

1

A Initial Decisions: Defining the Requirements

The Team

Improving a building is a team effort onwhich everyone is on a continuous learningcurve. Team members will each bring to theproject their own set of preconceptions,skills and information. Knowledge and un-derstanding must be shared for the projectto succeed.

• Conservator• Manager• CuratorFamiliar with collections and tight budgets.May not be familiar with building works. Maybe unimaginative, take too much for granted orassume too many responsibilities.• Developer, valuer/surveyor, estate agent• Architect, engineer• ContractorMore familiar with peoples' needs than objects'needs. May not be knowledgeable about conser-vation or requirements of funding bodies. Maysometimes over-react and/or miss importantpoints.

Staff and financial resources must be allocatedIt costs much less to get things right fromthe start than to put them right later. The En-ergy Design Advice Scheme of the Depart-ment of Trade and Industry operates fromfour regional centres and may be able to pro-vide financial assistance with consultancycosts for energy efficiency studies.

Allocate sufficient time and budget for teammembers to GET TOGETHER to:• explore real needs;• visit buildings of interest;• exchange briefing information;• prepare a strategic list of key points to be

achieved;• examine specifications and drawings;• have regular progress meetings;• undertake a thorough handover; and• identify any outstanding problems with the

completed building ('snagging').

Initial Decisions

Requirements must be determined by the in-tended use. Items and groups to be storedmust be assessed for size, weight, access, se-curity, fire safety and environmental control.

Related areas and activities must also be iden-tified. If several departments, sites, or organi-sations share a new facility its viability mayimprove, but if things will need grouping byownership, space requirements and costs willincrease. Will a poor building or one on ashort-lease be a cost-effective stop-gap or awaste of time and money? Will an expensiveone be a wise investment or might the outlaythreaten other budgets and staffing?

The Search

Once a general strategy has been agreed, amore precise brief will be required to providecriteria for a search or new design. Any ex-isting land and buildings must be evaluatedagainst the basic requirements:• Do they meet them?• If not, could they be modified to do so?• At what cost?• If an attractive building is not entirely

suitable, should the search be widened orcan the brief be satisfactorily altered?

• Are there legislative restrictions (egplanning, building regulations, listing)?

If there are several options, the work neces-sary for each to meet the brief will need to becosted, at least in broad terms.

An Outline Brief

A written brief defines the requirements. It isneeded at an early stage, even to modify anexisting building. It can start short, evolveas a record of the progress of ideas andagreed requirements, and also help to in-form new members joining the team. The fi-nal clear statement of requirements can berefined to assist specification, be referred toin the building contract, and used to help en-sure that the requirements are met. If thework is to be in stages, later phases need notbe specified in detail, but must be sufficientlywell explored to ensure that any subsequent

disruption, inconvenience and abortivework is kept to a minimum.Requirements can be expressed in terms ofthe performance needed (see the Table oppo-site). Fundamental issues are size, securityand environmental standards. References[7,19,21,22,23,24,30 and 38] contain muchuseful information.

Size and arrangementThis depends on many things:• What and how much is to be stored?

Consider floor area, height, weight, accessand environment (see below).

• How will different classes of items be stored,how tall and how densely?

• Will the volume of stored items grow? Howfast by how much? Remember that whenitems are properly packed they are likely totake up extra room.

• How easily will items need to be accessedand by what means?

• How will items be moved - what is theirsize, weight and fragility?

• How frequently will they be moved: forresearch, display, exhibition or merelyrearrangement?

• Will there be other uses such as exhibition orconservation workshops, research studyareas or wider public access? For how manypeople? Will this affect how facilities arearranged?

• Will ancillary facilities be required -catering or reception areas, study andmeeting rooms, waiting areas, toilets?

Always plan to make maximum use of theavailable volume with mezzanines, etc. Youmay not think you will need them but storestend to fill up all-too-quickly.

Security and fire protectionWill you be putting too many of your eggs inone basket? Will they be safe? If necessaryrefer to MGC's security adviser.

2

The Process

STAGE ACTIVITIESInception Appoint core team.

Define function and needs for spacelocation, access, staff, tenure.

Building decisions Finalise brief.Decide environmental needs.Find finance/set budget.Specify works. Seek approvals.

Production Detailed planning/design.Obtain tenders. Select contractors.Inspect progress and standard ofworks.Plan occupancy and move-in.Building services commissioning.

Occupancy Completion and handoverDrying-out the building.

Move in Snagging and 'tweaking'.in use Monitoring, review & feedback.

The sequence of activities until production will vary for each project, as perceived needsare matched to available buildings.

A Good Storage Building

• Structurally sound and weatherproof.• Appropriate, secure and fire-safe

internal environment for the storedobjects.

• Good local environment, avoiding dust,chemical pollution, salt and pests.

• Good access, circulation and headroom.• A convenient and safe location.• Affordable capital cost.• Low-energy and maintenance costs.• Space for support staff and visitors.

Cost level

Trade-offs will be necessary between costsof building, upgrading, storage equipment,and environmental control. Make sure youcan afford to meet the recurrent costs.

Environmental control• Do all the items have similar needs?• Are any exceptionally sensitive?

• Are any particularly tolerant?• What conditions have they become used to

in their existing storage?• What are the existing conditions? Will they

be suitable for at least some items?• Will holding areas be needed for

acclimatisation and decontamination?• Will deliveries and vehicles adversely affect

conditions?• Who will work in or visit the store?

• Will comfort and storage needs conflict?• Do you have any specific preferences or

dislikes of equipment and controls?• Can sensitive items be placed in separate

zones, if possible buffered and enclosed, inthe plan or the height of the building, bymore tolerant ones? (See Section I). This willimprove stability and reduce buildingservices and energy costs.

Some issues to be Considered in Briefing and in Selecting Buildings

3

Characteristic Purpose

Locat ion museum staff

researcherspublicimage

tenure and budget

Access vehicles

object movement

people

Size floor area

height

future expansion

Securi ty access controltheft/vandalism

fire/flood/pollution

systems and failures

Floor loading general

special

adding areas

Room types objects

other activities

future changes

Env i ronment variations

ranges and tolerances

control mechanisms

utilitiespests

Performance required

Acceptable travel time, from relevant locations. Public transport desired for visitors and staff. Staffpermanently on site. Will relocation disrupt them? Proximity to shops, food.Numbers and frequencies expected. Amenities they may require locally.Ease of identification, image, visitor numbers and frequency expected.Unprepossessing and undermaintained buildings may influence public, staff and funders' percep-tions of your operation and attract vandalism (so may some flamboyant buildings).Lease or purchase? Length of lease and effect on forward-planning. Cost and rental levels.

Number of car-parking spaces for staff and visitors. Right of access (exclusive where possible).Likely vehicle sizes and turning circles, especially during filling of the building. Will delivery vehiclespark outside or enter a holding area for unloading and subsequent acclimatisation/decontamina-tion? Fire and emergency access to all parts of the building.Maximum dimensions of objects and the carrying equipment needed for them: turning circles,width and height of doors* weight for loading capacity, through routes to final location. Type anddimensions of fork lifts, if to be used. Correct heights for handling, moving and seeing.Access for disabled people, convenient routes without unnecessary doors between frequentlyused locations. Suitable secure provision and segregated circulation routes for public access.

Amount to be stored by what method. Needs for separate rooms. Suitable allowances for accessboth within storage and for general circulation between different parts of the building. Will re-packing increase the volume of stored materials? Other activities to be included, with overall area,typical number of people, special requirements (access, view, proximity to other spaces, servicing,ventilation requirements, etc.). Minimum area acceptable on each floor.Height of racking - access and loading considerations - check height to structure at eaves if theroof is pitched. Is a multistorey building acceptable? How many storeys maximum? What lift capa-city is needed? Can you use the available height efficiently? Are mezzanines useful?How much additional space may be required in the future? Must it be in one building? Could thebuilding be extended or could there be a separate building on site, or elsewhere?

Consider how different types of people will use the building.Security standards to be reached. Policy on 24-hour guarding. Types of lock and alarm systems to beused. Block off any unnecessary windows, doors and hidden spaces. Site perimeter security, qualityof neighbours and extent of continuous surveillance.Check hazards from neighbouring and previous land uses. Plan to minimise risks. Review health andsafety for staff and visitors. Alarm and extinguisher requirements. Are sprinklers necessary or ac-ceptable? Pest control: inspections and treatment. Dust control: air intake filters. Hazards frompiped services and rainwater systems: water bars to boiler/plant rooms.Complicated systems can fail more easily.

Typical normal contents of shelves/racks, typical weights. Point loads may need spreaders - under-rack feet, for instance. Are floors sufficiently strong, flat, level and easily maintained?Review weights of extra large objects or fully loaded densely packed racking systems - for exam-ple, archives require three times normal office-loading capacity.Mezzanines or additional storeys. Information about existing structures may be hard to find. Checkweights: strengthening and new foundations under columns may be needed. While the building isempty, consider adding foundation pads for future mezzanines.

Is separation needed - by classification, type of environment, type of ownership, type of security,degree of public access or type of storage system.Staff: offices, workshops, laboratories, amenities (kitchen, rest area, toilets).Processes: plant, fumigation, drying, refrigeration, etc.Public: study areas, viewing, exhibitions, amenities. Appropriate circulation routes.Different items to store, new checking methods, more access by the public, altered requirementsfor environmental control, foreseeable within, say, next five and ten years.

Markedly different needs for relative humidity, temperature, light or air quality need grouping andquantifying. Different access requirements may require subdivision into further zones.Determine extent of deviation from ideal to be tolerated, eg % of week or year, rate of change ofconditions acceptable and spatial variations (eg with height).Automatic adjustment may control humidity, temperature or combinations of the two. Locatemonitoring equipment for environmental conditions, preferably providing past records. Will com-puter monitoring and remote control be needed? Who will make adjustments and how? Lightingcontrols need careful thought for effective and economical operation.Existing services: existence, condition, adequacy, capacity required. Potential for upgrading.Likelihood. Eradication and precautionary measures. Monitoring procedures.

B Typical Characteristics of Industrial Buildings

Properties of Typical IndustrialBuildings

Most industrial buildings will need upgrad-ing to suit all but the most robust museumitems. Nearly always work will be requiredto improve weather tightness, air leakage,insulation, security, internal environmentand pest control. Many will also need newrooms or control zones inside (see Section]).

Rent or buy?Think long-term. For a short lease, is itworth the bother of the move? Can you af-ford the alterations you really need? Andwill you get value from the money that youdo spend? For a long lease, some landlordsmay be prepared to make improvements foryou and charge for them in the rent. It is al-ways worth negotiating, but for specialiseditems you may be better off buying.

Type and Original Use

The plans, sections and notes on the rightoutline a few common building types, theircharacteristic features and the problemsand opportunities they often present, bothas buildings [45] and for museum storage.Desirable and undesirable characteristicsare often present together, so careful assess-ment is necessary. WARNING: if numerousthings are wrong, rebuilding might easily be-come more cost-effective than alteration andupgrading.

The same structural forms recur in build-ings designed for a wide range of industrialuses. However, buildings originally forstorage (especially the newer ones) are oftenbetter in the aspects that are most difficult tochange, for example, shape, structure andrelationship to roads and other buildings.On the other hand, public transport accessto storage buildings is often poor and fewbuildings will have been constructed with aview to long-term storage of valuable items,sensitive to fluctuations or extremes in en-vironmental conditions.

Structural Systems

Suitable industrial buildings tend to be ofthree distinct types:

• Loadbearing masonryTypically nineteenth century, usually threeto six-storey. Massive construction, oftenwith limited ceiling heights and internalsteel, cast-iron or timber columns at closespacings.

• Steel or concrete frameMultistorey, typically early to mid-20thcentury, with brick cladding or infill, plusgrowing use of concrete or lightweightcladding from the 1930s on.

• Single-storey shedsMany shapes and sizes. Four common typesare identified here. Roofs often metal orasbestos cement sheets, not alwaysinsulated, often with rooflights. Walls aresimilar, or of brick or block, at least at lowlevel. Floors usually concrete, not alwaysreinforced and seldom insulated.See Section G.

Desirable and Undesirable Features

Desirable features• Simple rectilinear floor plan.• A large opening for loading.• Where appropriate, high ceilings to allow

tall storage units or mezzanines.• Goods lifts when using several floors.• Clear internal spans to ease movement.• Smooth flat floors, no level changes.• Designed for heavy loads.• Site security (on some modern industrial

estates and business parks).• Low, anonymous profile (unless an image is

required to attract the public).See also references [40] and [41].

Undesirable: Need altering• Poor and poorly insulated roofs; walls and

floor may also need attention. Uninsulatedand leaky doors.

• Poor airtightness. See Section H.• Valley gutters, particularly if no relief

overflows. Internal gutters and pipes.• Cracked, uneven and dusty floors.• Too many rooflights and windows•• Unsuitable heating, ventilation and lighting.

Damp.• Inadequate mains connections.• Poorly maintained, decayed and infested.

Undesirable: Hard to modify• Close to dirty industrial processes.• Constructed of unsuitable materials.• Insufficient loadbearing capacity.• Many closely-spaced columns.• Low standards of construction.• Isolated, unsafe vandal-prone locations.• Saline/coastal/marshy locations.• Land prone to flooding/dampness.• Poor physical security. Lightweight

construction prone to ramraiding.• Damp or flood-prone basements.• Listed building status may be restricting.

Hidden hazards• Concrete decay, especially where wet.

Asbestos in insulation and cavities.• Built-in timber rotten (eg joist ends).• Built-in steel corroded.• Industrial waste contamination of land and/

or buildings. This and asbestos can be veryexpensive to deal with: if found late otherwork may need to be stopped.

• Water ingress, especially gutter leaks.• Restricted energy choice and availability of

mains supplies in some areas.

4

Common Types of Industrial Building

Location andopportunities

Built in nine-teenth centuryto before WorldWar 1Usually built ondeep inner city orold rural sites.Can appear darkand forebodingbut its charactercan be exploited.

Interior framedBuilt off roads;usually a mix ofbuildings.Mix of sizes andshapes of build-ings allow differ-ent uses.Good basic con-struction.

Universal shedBuilt in smallsuburban clus-ters, layout ishighly variable.Great potential forreuse and refurb-ishment.Open layoutusually allowseasy access.

Concrete portalframe shedUsually front ontoslip roads on rib-bon developmentsites.Cheap form ofbuilding; can bereclad and up-graded (or demol-ished).

Sawtooth shedBuilt in industrialestates; may beused on a deepsite.Large continuousspaces available.

Modern portalshed 'box'Built in industrialareas.Usually has betterquality landscap-ing.

Typical floor plan

Building typecharacteristics Typical section

Thick wall; heavymasonry (stone orbrick, eg cottonmills).Columns, piers,trusses or beams;Multistorey.

Multistorey build-ing, flat-roofedwith concreteframe or steelframe.Infill cladding -brick or panels -eg flatted fac-tories.Purpose-built forlarge companies.

All built fromnineteenth cen-tury to World WarII.Single-storeywith truss roof,usually pitched.Brick walls.Examples are gar-ages and work-shops.

Built between thewars and after-wards.Single- and dou-ble-height, possi-bly with 'domestic'office blocks at-tached.Example is thestandard factory.

Built in 1950s.Single- (somedouble-) storeywith asbestos andtranslucent roof.

Built in 1960s on-wards. 'Single- and dou-ble-storey withprofiled coatedsteel roof andcladding; from or-dinary type tohigh-tech style.

Typical features and some opportunities asmuseum stores

• Strong form, interesting spaces.• Architectural features, trusses and

windows, good stone and brickwork.• Definitive presence.• Often good floor loading.• Much space available.• Some floors can be 5 m or more in height,

giving space for mezzanines.• Often possible to remove parts of floors and

walls quite easily.• Some in good city locations.

• Some interesting architectural features,but not usually as strong as above.

• Independent structural frames which canoften be sound.

• New cladding can be applied if needed.• Usually has facilities that can be upgraded

(offices, lavatories).

• Easily identifiable building with character(but many of the best ones have oftenalready found new uses).

• Solid brick walls, easy to change.• Traditional construction, often

straightforward to repair.

• Frame basically relatively simple to reclad.• Access usually straightforward.• Cheap building/site.• Does not need a lift.• Offices often situated between visitors'

approach and storage space.

• Roof profiles very varied, including steeland concrete, shells, top hat' sections witha central raised part, etc.

• In urbanised areas of large cities and oldIndustrial estates'.

• Usually large areas of space available withminimum column interference.

• Usually reasonable access and space aroundbuilding.

• Modern buildings, built relativelyrecently.

• Should have some amenities.• Usually sound structural specification.• Relatively easy to reclad and/or upgrade and

reroof.• Car parking, adequate access, loading, etc,

will all usually be in place.• Typical Advanced Factory Unit (AFU).

Disadvantages and constraints in convert-ing to museum stores

• Often too many storeys.• Will need lift.• Too many large windows: security, heat loss

and gain (may need to be blocked).• Minimal insulation; will often need more,

especially to roof.• Can be too big and may need sharing with

others.• There may be security and risk problems if

access is shared.• 'Listing' may restrict alterations.

• If structure was designed or used forspecific industrial process, shapes orspaces may be inconvenient and thebuilding or the land may be polluted.

• Metal windows and roof lights will oftenneed replacement (but openings may needblocking anyway).

• Concrete may be decaying.

• Siting may be difficult.• Access may be awkward, particularly in

residential areas.• Space available may be too small or

compromised unless several units can becombined.

• Asbestos cement commonly used.• Roof structure may be unsound.

• Typical locations are often lacking infacilities and amenities.

• Local environment can be poor and in anindustrial area.

• Failures at roof junctions and internalgutters are very common.

• Asbestos cement cladding, if powdery, is ahealth hazard and may need totalreplacement.

• Concrete might be decaying.

• Too much natural light for museumstorage. Glazing is an environmental andsecurity risk and may leak.

• Valley gutters risky: take care.• Compartmentation, if needed, may prove to

be awkward.• Roof structure may be corroded/weak.• Generally not recommended, but there are

exceptions.

• Sometimes the ceiling height near theeaves can be too low for a mezzanine.Minimum desirable 4.5 m clear belowstructure, 5 m or more preferable.

• Untried or low-cost short-life claddingmaterials can fail, look unattractive, andmay need replacing.

• Poor quality insulation will deteriorate andoff gassing may affect stored objects.

• Airtightness is often poor, even in new andostensibly well-insulated buildings.

• Check condition of concrete.

5

c Evaluating Sites and Existing Buildings

Evaluating Sites and Buildings

In choosing a particular site or building, orin assessing a building which happens to beavailable, one can learn from good prece-dents and bad experiences. These may notonly be technical: for example, staff may beunhappy to go alone to a large empty build-ing on an isolated site.

Professional surveys may seem expensive,but for shortlisted buildings they are essen-tial. Technical data necessary to assess per-formance (eg design floor loadings, likeli-hood of hidden defects, budgets for repair)can be difficult to get. Accurate drawingsare essential to ensure efficient planningand selection of storage equipment. Thosenot familiar with interpreting drawingsshould also review possibilities on site.

The five boxes on this sheet outline aspectsof sites and buildings which need to be com-patible with your requirements:

1. Site Location.2. Site Coverage.3. Building Form and Type.4. Layout: spatial configurations.5. Construction: checklist.

1. SITE LOCATIONSite surrounded by development

• Local social amenities (catering).• Usually better public transport.

but• Higher land values.• Limited expansion.• Vehicle access sometimes difficult.

Isolated industrial site/estate

• Room to expand, room for vehicles,• Less conflict with neighbours.

but• Security more of a problem.• Little infrastructure for public access.• Staff may feel isolated or unsafe.

2. SITE COVERAGE

90%city block

60%rambling complex

40%single building

40%several buildings

• Storage all together.but

• Overdense, reliant on lifts.• Higher maintenance.• Access, loading and parking difficult.

• Courtyard can be attractive,• Potentially good security,

but• Limited vehicle access and loading.• Entrance may be difficult to define.

• Recognisable image to outside world,• Potentially good security.

but• Strung out and may be wasteful.

• Best for incremental expansion,• Parking and loading flexible.

but• More elaborate maintenance,• Security and control more difficult.

3. FORM AND TYPE OF BUILDINGSWIDELY AVAILABLE ON THEMARKET

• 'As found' spaces:eg caves, fortifications, cellars, viaductarches.

• Higher specification:Heritage and polite architecture egchapels, institutions, schools, post andtelecom buildings.

• Built for manufactur ing:

• Purpose-built for storage:

Opportunities/advantages

Special character but usually impracticalfor the long-term.Large volumes available that no-one elsewants, cheap.Often thermally stable but too damp.Possible use as outer envelope into whichsecondary containers are placed.

Character can be exploited.Enhances a place where people wil l beworking.Can be in a pleasant part of town, neigh- jbouring amenities, (catering, public trans-port).

Can have individual character.Usually equipped with office space and fa-cilities.Can be used for control, and study areas.

Usually planned to deal with vehicles, load-ing.Usually on one major level, can use fork-lifts, pickers.Relatively easy to build structures inside.

Constraints/disadvantages

Access usually inconvenient.Particularly difficult to waterproof, insu-fate, draughtproof and/or ventilate.Local pollution, low qualitySometimes too much of the area and envir-onment is difficult to control.Prone to vermin.

Access often awkward.Total building often covers plot.Limitations of architectural features,structural systems and room shapes andsizes.Heritage status, and especially 'listing' mayrestrict scope for alterations.

The building enclosed specific processes,creating odd shapes and volumes.Old plant/machinery or noxious residuessometimes difficult to remove. Landand/or building may also be polluted,General environment can be harsh.

Insulation often poor or absent.Poor performance building components,may lack robustness and durability.General environment often uninspired andunderpopulated.Security problems in location/isolation.

5. CONSTRUCTION CHECKLIST

Flat roofsCheck weatherproofing, adequate drai-nage outlets and falls* security and insula-tion.

Flimsy or fragile roofsIdeally rebuild or severely limit access,strengthen key points for maintenance.Consider security and pest implications.

Parapet and valley guttersAre gutters and downpipes adequate andall joints sound? Check for evidence of leak-age. Beware leaves and snow. Could waterbe blown back and dam up in valley guttersin a high wind? Consider escape spouts fordownpours.

RooflightsCheck weatherproofing. Remove and roofover in storage areas. Fit blinds in areaspeople use regularly. Replace and fit safety/security glass in office/amenity areas.

Asbestosinspect thoroughly. If at all friable, encapsu-late or ideally remove.

"Too many windowsBlock securely, incorporating adequate in-sulation. If windows are retained exter-nally, ventilate the space behind them tooutside air to reduce risks of decay.

BasementsCheck for damp, flood risk and insulation. Iffor storage, waterproofing, access/fire es-cape and ventilation may need upgrading.

AtticsCheck floor loadings, fire safety/escape,security, weathertightness and insulation.

Roof structure protruding downIf potentially restrictive, seek structuralengineer's advice on possible removal.

Very high ceilings and roofsTest possibility of mezzanines. Can existingstaircases be extended to fit? Consider in-sulated suspended ceilings.

Too many columns and supportsExamine plans to locate 'pinch' points. Takestructural engineers advice about addingbeams to allow key columns to be removedor relocated.

FloorsTake structural engineers advice if weak orcrumbling. Sometimes possible to consoli-date, but full or part replacement may beneeded, or new foundation pads for mez-zanines and racks. If uneven or dusty, con-sider levelling and sealing. Avoid changes inlevel - ramps take up a lot of space.

WallsCheck for stability and damp. Check thatsheet cladding is sound.

Heating, etc., in placeTake building-services engineer's advice onsuitability, useful life, optimum operationand potential for reuse and upgrading. Ex-isting systems will often be unsuitable (seeSection K).

4. SPATIAL CONFIGURATIONS OFBUILDINGS WHICH MAY BE FOUND

Street front building with yardeg within the city.

Many scattered buildings on fenced orbounded siteeg rural/farm or on an industrial estate.

Single unit within block of units (withother users)eg within a city block or a unit on an indus-trial estate.

L-shaped buildingor other complex shape on its own plot.

• Simple approach to site possible.• Environment can be upgraded and made

good.but• May have wasteful yard space, but this

could be useful for additional functionsand extending the building.

• Different buildings available for differentenvironments.

• Room for expansion and gradual upgrad-ing.

• Easily converted to 'resource centre'.but• No single protected loading area.• Higher running and maintenance costs.

• Economical development.• Simple space, might expand next door• Anonymity may assist security.but• Neighbours may be incompatible (eg

poor image, polluting, damp).• Unglamorous as resource centre.• Possible security problems if there are

concealed rear fire-escape passages.

• May have pleasant prospect from road.• Potentially attractive courtyard entry.but• Can be uneconomic to supervise

L-shape for people and vehicles.If adjacent space is built on by others,prospect declines and neighbour may beincompatible.

7

D Storage Planning and Systems

Storage Classifications

Many characteristics must be borne in mindwhen planning, and building profession-als will not necessarily think of all of them.Needs and priorities will vary with the mu-seum and its stored items.

Time scaleThe length of time objects will be stored andfrequency of viewing will affect packing andaccess, for example:• Short Term: recently accessioned or awaiting

dispatch or conservation.• Medium Term: often material held pending

decisions. Can you save space by allocatingtime to decide now?

• Long Term: Study collections of high-qualitymaterial on which items are drawn forinspection and exhibition.

• Loan Collections with frequent in and outflow.

Size of objectsThis affects handling methods and accessspace. Mechanical handling, usually byforklift, is increasing with health and safetyrequirements, even for quite small items.• Small: can be lifted safely by one person.• Medium: lifted by a team and moved on

trolleys or pallets and forklifts.• Large: size and/or weight requires powered

transport: forklifts or cranes.• Extra large: Over 15 m long or 10 tonnes.

Needs special provision.

Different materialsAudit what you plan to store [20, chapter 3]and consider its needs as accurately as pos-sible, see references [2 and 4]. Items whichneed very different conditions may haveto be in separate areas or specially packed.Compromises will often be required, bothfor convenience and economy, and for ob-jects made of several materials (eg a cart ide-ally requires metals dry bodywork mediumand wheels damp!).

Case Study — Storage strategyBar End — Winchester

• A fixed shed for a growing collection,• Initial budgets allowed for only 30% of the

racking to be mobile.• Supplier chosen had a good service record

and had fixed and mobile systems which usedthe same racks.

• Tracks for mobile racks were fitted at thestart, level and flush with the floor.

• As pressure for space has increased, addi-tional racks and mobile bases have been pur-chased.

• The occupier would now recommend usingpowered trolleys and forklifts for horizontalmovement.

Environmental NeedsThese vary from object to object, and anyvalues chosen will be a compromise. Pro-tection from excessive light and an appro-priate range of relative humidity is usuallymost important, preferably at cool tem-peratures, see Sections E & F and graph below,adapted from reference [46].

Storage Planning

Approaches vary with type of object:Large or awkward items: free standingMedium to heavy items: pallet rackingLight boxes, papers: mobile rackingLight but fragile items: fixed rackingFlat textiles: suspendedShallow fairly light objects: drawersSensitive/unique items: own microclimateHigh value small items: strongroomMaintenance stores: lower security.Once moved, and if not labelled and assigned alocation, an object can be 'lost' forever. Use themove as an opportunity to improve records.Seek and allocate resources for this.

Make good use of the volume of thebuilding; Do not pay for height you don'tneed. Racks and mezzanines, where suita-ble, can maximise floorspace. Pallets simpli-fy handling of heavy and bulky items. Low-cost volume may be useful as a buffer space(See Section K).

Use layout drawings to decide the best useof available space and plan lighting layouts,access routes, etc. You must make carefulmeasurements and you may need experthelp. 'Free' advice from storage manufactur-ers can be useful, but avoid getting lockedin' to one supplier's range.

Points to Watch• Poor planning wastes space and can

make access difficult. Room sizes andareas, column spacings, width of secur-ity corridors, and entrance/exit pointswill all affect layout and rack sizes.

• Plan the mix of objects to equaliseloads if possible. Floors may need rein-forcing for heavy and point loads.

• Full flexibility to place any object any-where will only be achieved at the ex-pense of reduction in volume stored.

• Plan for future mezzanines and sto-rage on top of internal rooms. Ensurethat access to them is easy and safe. Seediagrams opposite.

• Match the range of container and rackdepths, widths, and heights to the ob-jects. Space wasted at ends, front andtop of each shelf quickly adds up,

• Identify any special storage furnitureand equipment which may be needed.

• Allow for space taken by pallets andcontainers when calculating storageneeds. Nesting designs can reduce spacetaken by empty pallets and containers.

• Long runs of shelves are harder to planand access efficiently. Mobile racks sel-dom go beyond 12-14 m long,

• Floors must be smooth and extre-mely flat for safe and effective use oftrolleys and fork lifts. Tiny steps and hol-lows impede movement and shake ob-jects about. Ramps also waste space,For mobile racks, insist on tracksflush with the floor, positioned beforethe floor is finished, CONTRACTORSOFTEN PREFER TO PUT TRACK ON ARAISED PLINTH AFTERWARDS - AVOIDTHIS IF YOU CAN, PARTICULARLY IF TROL-LEYS AND FORKLIFTS ARE TO BE USED

• Keep lights and heaters away fromshelves. Ensure switches and powerpoints are easily accessible.

• Do not block air circulation: raiselowest shelves and keep racks awayfrom external walls, especially If theyare not well insulated. Plan for easycleaning and checking for pests.

• Remember that requirements for pub-lic access to stores is likely to grow Howwill you deal with it?

If You Use Fork Lifts• Allow sufficient space for movement

and turning.• Plan racks accordingly.• Use small simple equipment where

possible: it requires less manoeuveringspace and may not need trained opera-tors.

• Bulky fork lifts take a lot of space: ifyou really need them, consider mobilepallet racking or side-loading equipmentto reduce aisle widths and improve spaceuse.

• For access to mezzanines, considerhinged sections of guard rail with pad-bolts.

8

Try to Use Relationship Diagrams Relationship diagrams like this areuseful both to plan and to assist dis-cussions with building profession-als. Major spaces are shown as boxes(minor spaces can be added too), withfunctions and activities written insideand linkages shown as lines. Here themain storage area (at the top) is linkedto three interrelated groups below:process, staff and public areas. Oftenthese four parts will need to be segre-gated, particularly where visitorsneed to be controlled. Other require-ments can be included, here surveil-lance of vehicles and visitor accessand rooms requiring some daylight.

Do not waste vertical space

Do not place lights below the roof struc-ture or above racks. Use the spaces be-tween. See the sectional sketch above.

Do not waste volume, but do not pilethings too high. If a large fork lift is neededfor some items, zone vertically, using mez-zanines, or horizontally using some wideand some narrower aisles. Provide forkliftaccess gates in mezzanine railings whereappropriate. Avoid low-roofed buildings inwhich you hit your head on the beams: thisis extremely inconvenient and you willneed hard hats.

Eventually you will always want to putthings on top of enclosed spaces such as of-fices and secure stores. Make them strongand flat, avoiding obstructions by cables,pipes ducts, etc. Allow space for access.Plan to link them to mezzanines, etc., at asingle level. Even small level changes are dif-ficult to negotiate.

If you have mezzanines in separate parts ofthe store, as in the plan above, try to linkthem up. This will improve access, reducethe number of escape stairs required andmaximise usable area.

Decide if vehicles are to enter the loadingbay, and if so, up to what size - a Lutonvan, a pantechnicon? Usually one shouldhave secure, and preferably airtight andinsulated doors between store and load-ing bay. Storing large awkward items nearthe loading doors, and smaller onesfurther in will save aisle and manoeuver-ing space. If practicable, a goods entranceon the 'long' side (as here) may avoidwasted circulation space.

9

E Environmental Control: Requirements and Principles

Storage Conditions for Objects

If the building can potentially meet the basicrequirements of watertight, secure, accessi-ble, clean and pest-free shelter, then themain priority becomes the internal environ-ment: temperature, RH (relative humidity)light and air quality.

Considering Standards

At present there is much debate aboutacceptable standards. While publishedguidelines (eg [4]) must be consulted, eachcollection is unique and appropriate solu-tions must be chosen to suit its particularneeds and circumstances [46], includingthe environment to which it has become ac-climatised [20, chapter 2]. Most containvarying proportions of:

1. Robust items needing little more thanavoidance of extremes.

2. Intermediate items needing conditionswithin a defined range.

3. Sensitive items requiring stability andsometimes close control.

Stores for large or robust objects often have amultipurpose main storage area, plus a fewsmall rooms or containers for the more sen-sitive or valuable items. In practice it hasproved difficult to get the right standard forthe main area: too often one finds intermedi-ate items in thermally poor spaces with fewservices, and sometimes quite elaboratelyserviced places for largely robust collections.Building professionals, often used to design-ing primarily for human comfort, may needto review their assumptions in relation topriorities for effective and economic collec-tion care, for instance:

• Unlike people, most objects are more affectedby moisture levels than by temperature.

• Most objects prefer low temperatures, whichhelp to slow down chemical and biologicaldecay, although increased moisture levelsmay occur at low temperatures andcounteract this.

• Robust stability may be preferable to energy-dependent constancy.

Are variations acceptable?Published museum standards often assumetemperatures at comfort levels, with RHscontrolled within narrow limits. Necessarilythey are for typical circumstances and notfor specific items or collections which mayhave survived well in different environments[11]. In storage there may be more flexibility:comfort is often less of an issue, a degree ofdaily and seasonal fluctuations in condi-tions may be permissible, and sensitive itemscan be segregated.

Many intermediate items may tolerate RHswhich vary by ± 10% about a suitable meanvalue, plus occasional slow excursions be-yond, within overall limits of typically 30-70%, see [12] and [46]. While metals preferRHs at the low end, higher RHs may be ac-ceptable if they are clean and machinerycan often be protected with grease. Usingthe strategies outlined opposite, improvingthe building's performance (Section H), andusing zoning principles (Section]), one maybe able to bring suitable buildings (or partsof them) to appropriate intermediate stan-dards while avoiding unnecessary capitalor running-cost expenditure on buildingservices.

Indoor Air Quality

Heat, moisture and pollutants are releasedinternally by the occupants, their activitiesand equipment. Some stored objects alsorelease pollutants, which can affect bothpeople and other objects. Some building ma-terials also emit volatile chemicals, dust andmoisture (rising and penetrating damp).These problems must be minimised and sui-table ventilation provided [34].

The influence of the Building

For long-term survival of a collection in per-manent storage, environmental controlshould ideally be primarily a 'passive' func-tion of the building (with appropriate sto-

Moisture-related deterioration

• Dry conditions are good for inhibiting corro-sion, chemical and biological attack, but or-ganic materials shrink and may becomebrittle.

• In damp conditions, most organic materialsexpand and soften. Risk of corrosion and bio-logical activity by moulds, insects and fungialso increases greatly. While some mouldscan propagate at RHs as low as 60%, mostpractical dangers start at 75% RH, a levelabove which constrained textiles may alsoshrink dangerously as their fibres swell,

• Animal glues soften and slip above 80%. Ve-neers may then crack when the RH subse-quently falls.

• RH fluctuations can be problematic, particu-larly for physically restrained organic materi-als, composites, and hygroscopic salts liableto expansive recrystallisation. However,many museum objects are not affected byfluctuations which last less than one hour.

• Prolonged excursions to a low RH (typicallyunder 30%) can be very damaging. In theUK this is most likely if buildings are over-heated in cold spells (below freezing outside).

Adapted from reference [12].

rage and management policies), and power-assisted only to the degree absolutely neces-sary.Buildings modify the internal climate usingthe following main mechanisms:

• Sheltering from the weather.

• Restricting the passage of air.

• Impeding the flow of heat and moisture, bothin and out.

• Storing heat and moisture in their fabric andcontents.

• Trapping solar radiation.

The effects are often, but not always, benefi-cial. Local climate is of course influential, egdampness problems in buildings in water-side locations or in areas with heavy rain-fall.

An Appropriate Use of BuildingServices

In recent decades, dependency upon ever-more complex heating, ventilation and air-conditioning (HVAC) systems has tendedto rise while the role of buildings and con-tents in helping to stabilise conditions hasoften been ignored. Today, the wisdom of thisreliance upon engineering systems is inquestion. Expensive to buy, systems can beexpensive (sometimes too expensive) torun. Lower-powered systems, designed to 'trimthe environment to avoid adverse conditionscan potentially be less expensive, less energy-hungry, safer and more reliable than higher-powered systems upon which the collection iscompletely dependent.

Control Strategies

Strategies which set out to modify condi-tions by no more than is necessary to lookafter the objects, are particularly appropri-ate for storage buildings where:

• Budgets are often tight.

• Preservation can often be allowed to takeprecedence over human comfort (but staffwill also need somewhere to go which haslocal heating).

• Inputs of heat from lights and heat andmoisture from people are often small.

A range of alternative strategies shouldbe considered, including those outlined inthe Table on the facing page. While close-control air-conditioning may sometimes bethe only way to provide the necessary envir-onment, it should be seen as the last resortand applied only in circumstances and inareas where it is really needed.

10

The seven strategies outlined in the Table be-low range from completely free-runningthrough to close control within a narrowband. In practice many stores will use varia-tions, combinations and hybrids to suit theirown needs. Practical examples can be foundbelow, and in the case study in Section M.Appropriate solutions will also depend upon

the balance between comfort and storage.For example, where visits are made forsecurity and checking only criteria for eco-nomical storage can dominate and conser-vation heating may be suitable. If thebuilding is a resource for the general public,comfort will be more important, at least insome areas. Additional systems may also be

needed to improve comfort and to meetworkplace legislation. For instance, staffmay require a warm room, or local electricradiant heaters (see Section K) which can beactivated for short periods as required. How-ever, if the contents are worked on and ex-hibited frequently, then full control maybecome necessary.

11

Approach

Approach 1. No Heating

Shelter only. Follows externalconditions if well-ventilated.Frost protection is desirable.Uncomfortable in winter

Approach 2. Comfort Heating

Conventional heating systemwith room temperature con-trol. For economy the build-ing needs to be relativelywell-insulated and airtight.Choose the lowest tempera-ture practicable.

Advantages

Useful protection for objectsnormally kept outdoors or insimple shelters. Low runningcost. If internal, may be insu-lated by neighbours.

Well understood. Suitable forpeople.

Approach 3. Heating with Humidification

Conventional heating systemaugmented by local or centralhumidifiers. The store needsto be insulated to good prac-tice levels, with good air- andvapour-tightness.

Permits people to be comfor-table while avoiding low win-tert ime relative humidity(RH) for objects.

Approach 4. Conservation Heating

The heating is operated tokeep winter RHs within anacceptable range for the ob-jects. Extensively used by TheNational Trust, Best for lar-gely unheated stores. May beuncomfortable in winter.

Low-powered with modestoperating costs. May be ableto re-use some existing heat-ing systems under humidistatcontrol.

Approach 5. Dehumidification Only

Often no direct heating.Store must be relatively air-tight. Particularly useful formetals needing a dry envir-onment year-round. Uncom-fortable in winter unlessheating is added.

Approach 6. High Inertia

Relies largely upon a heavilybuilt, airtight, well-insulatedstore for stability of tem-perature & RH. May use low-powered heating, ventilationand humidity control. See re-ference [39].

Approach 7 Full Control

A wide range of options forheating, cooling, ventilationand humidity control is avail-able, The store needs to beinsulated to good practice le-vels, with good air- and va-pour-tightness.

Better limitation of RH thanpossible naturally or withconservation heating. An en-ergy-efficient option whereheating is not needed for ob-jects or people.

Stable RHs possible with re-latively low energy input.Particularly useful for den-sely stored organic materialsand archives.

Can potentially be tailoredto any required specification.Attractive if future needs areunknown or uncertain (butso is waiting until you aresure what you really want).

Disadvantages

Wil l usually be too damp.Light, poorly insulated andventilated buildings can over-heat on sunny days, particu-larly if windows or rooflightsare large.

Air will often be too dry incold weather, particularly ifventilation rates are high. En-ergy costs will be high if thebuilding is draughty or poorlyinsulated

Relatively high running cost.Good control, reliability andair distribution is vital. Fit ex-tra humidity controls tosound alarm and shut downhumidifier if the RH goesabove limits.

Cool in winter, typically 5 Cabove external. RH rises insummer because the tem-perature required to limit itis too high. in well-sealedstores 'hygrothermal run-away' might occur unlessthere is a high temperaturecut-off.

Refrigerant-based dehumidi-fiers may not work well un-der about 10oC and may heatthe air too much. Desiccantsin chemical units may con-taminate stores - use inertmaterial (eg silicagel).

May not be appropriate if oc-cupancy rates are high. Ap-propr iate low-poweredservices can prove difficultto obtain, design and control.Possible 'hygrothermal run-away',

Capital, energy and mainte-nance costs tend to be high.Control and reliability is criti-cal and needs careful consid-eration. 'Flexibility' is nopanacea and its benefits mayprove illusory.

Comments Capital EnergyCost Cost

NA NA

Uninsulated metal roofs can drip condensa-tion on clear still nights. Widespread con-densation may occur after cold weatherBuilding may deteriorate.

£££ £££

Where possible avoid heating the wholestore to comfort levels. Greatest danger toorganic materials and composites if over-heating occurs when it is below freezingoutside. Designers may forget object needs.

££££ ££££

Useful for composites where comfort is alsoneeded. Humidification can cause overt orhidden condensation dampness in walls,roofs, and adjacent unheated spaces - re-view risks carefully.

££ ££ |

Effective even in stores which are not veryairtight. Higher summer RHs may often beacceptable. If they are not, supplementarydehumidification may be added (see Strat-egy 5 below).

££ ££

Maintenance costs can be high. Most chemi-cal desiccant units need ducts to outside airRefrigerant units usually need condensatedrains - buckets can be used instead butare not recommended.

££££ £

Internal heat gains in particular from lightsand fans must be kept to a minimum (this isalways desirable in any event). Used for ar-chives (see reference [8] for examples); ofincreasing interest for museum stores.

£££££ £££££

Often seen as the ideal but is sometimes re-gretted afterwards. Try to limit to areaswith high occupancies and/or exacting re-quirements. Needs good design, monitoringand maintenance.

F Natural and Electric Lighting: Systems and Strategies

Lighting

Light is destructive to many materials (in-cluding packaging), and can be one of thegreatest threats to long-term care.

• Light levels required for the safe use of thestore can be quite low. A safe rule of thumb is200 lux at 1 metre above the floor indesignated areas where perception of detailis required.

• Do not put sensitive items on top shelves:near lamps and rooflights the illuminationmay be much higher.

• Fit ultraviolet (UV) filters to all lamps whichmight shine onto stored objects, unless100% sure that they will only be on for veryshort periods.

• Minimise usage: arrange switches to stoplamps being on unnecessarily.

• Switch off lights as much as you can, to avoidunnecessary exposure, save energy andavoid unwanted heat gain.

Exposure to light

A cumulative lux-hour approach (illumi-nance multiplied by hours of exposure) maypermit higher light levels (say 500-600 lux)from time to time for detailed examinationand study. Mobile task lights can be helpful,but they must be mechanically stable forsafety and cool-running (normally fluores-cent) to minimise fire risk.

However, for items 'resting' in storage, lowerexposures are highly desirable, with items inthe dark or at least in very subdued light, foras long as possible.

Light sources and fittings

Tubular fluorescent lights in reflector fit-tings are normally most appropriate; othersources tend to cast too many shadows.Lamps should be enclosed for UV protectionand in case they shatter. Fittings should beabove the aisles in shelving and racking: thisneeds either careful planning or easy reloca-tion. To light the shelves effectively reflectorsshould be chosen in relation to mountingheight and aisle width. To simplify mainte-nance, lamp types and sizes should be stan-dardised as far as possible and there shouldbe easy access for re-lamping and cleaning.

Select the most efficient and low-energylamps and fittings you can afford, particu-larly for lights which may be on for long per-iods, eg for security, main circulation, andexternally. Further information is availablein references [13, 14, 28 and 29].

The well-chosen single tube fitting on the right cangive better illumination while using half as much en-ergy as the unsuitable twin-tube one on the left.

Light switchingIf the store is to be visited only occasionally,then switching in simple blocks may be ac-ceptable. Lights used by security patrolsand in main circulation should always be se-parately switched from convenient loca-tions.Where the store is regularly occupied, morecare is required: lights on unnecessarily notonly waste energy, but cause avoidable de-gradation to the stored objects. In well-insu-lated and sealed buildings and enclosures,they may also cause unwanted heating.Arriving at an empty store, it can be difficultto find the switches, so indicator lamps (andsometimes a little daylight) are very helpful.Indicators (and possibly switches) shouldalso be fitted outside the doors of closedstores and containers; otherwise lights maybe left on by mistake for long periods - wast-ing energy and possibly causing damage,both directly and indirectly.Corridor routes should be switched sepa-rately at all entrances and exits and storageareas switched locally. Different colouredswitches for corridor and circulation areascan aid their effective use. In areas of shel-ving and racking, consider controlling eachbank of lights from local switches at the endof each aisle, with through-aisles two-wayswitched from both ends. Consider timersto switch off lights after predetermined in-tervals, with management over-ride facil-ities to permit permanent lighting whenrequired, and with sufficient residual light-ing for safety.

If 'hands-free' operation is desired, eg whereforklifts are regularly used and all the lightswould otherwise be left on permanently, 'oc-cupancy sensors' may be considered: theseswitch on if they detect movement and/oroff some time after an area is vacated. Theyare not necessarily expensive and may alsobe convenient in corridors, WCs, storagecontainers and for security. Care must betaken to avoid nuisance and danger if thelights were to go off inadvertently.

Daylight and sunlightDaylight should be eliminated owing to itsdestructive effects, and security hazardswith windows and rooflights. Sunlight'shigh intensity makes it very much more da-maging, particularly to anything it hits di-rectly; and it may also heat the buildingsignificantly.Daylight however improves the appearanceof interiors and objects, and saves energy. Itmay be appropriate for:• zones in which all objects are durable:• parts of resource centres which are occupied

for much of the time; and• offices, workshops, study areas and rest

rooms.Where stored items may be affected, UV pro-tection is required (eg by a film - some plas-tic rooflight materials already absorb UV)and security hazards must be addressed.Rooflights and windows should be prefer-ably north-facing to restrict entry of directsun, and shutters and blinds are desirableto control light levels and to avoid unneces-sary daylighting during unoccupied periods.

Lighting for mobile rackingWith mobile racking, lights with a broad-spread distribution are normally run per-pendicular to the shelves. Try to avoid toomany lights shining uselessly and waste-fully on the tops of the racks by lighting themain circulation only and controlling aislelights in small groups, for example withpull-cord switches in the main aisle, justabove head height, or by suitable detectorsand/or remote controllers.

12

G The Building's Performance As a Protective Enclosure

General Requirements

To help control temperature and relative hu-midity stores need, in order of approxi-mately decreasing priority:

1. A shell which is structurally soundand watertight.

2. Low air infiltration to reduce un-wanted ventilation.

3. Good thermal insulation, to reduceheat losses and gains through thewalls, ceiling, floor and windows.

4. Limiting heat gains from the sun andinternal sources such as lights.

5. High thermal capacity, to reduce tem-perature fluctuations. Moisture sto-rage capacity is also often helpful.

Some issues are outlined here, with 'passive'solutions in Sections H and].

A building shell with good thermal perfor-mance, plus careful planning of space, willgreatly assist preventive conservation byhaving good, stable, low-energy 'passive'characteristics. With the right control strat-egy (Section E), this will minimise require-ments for energy-consuming equipment.Try to:

• Seek buildings which allow stable conditionsto be obtained straightforwardly, and ifpossible, cheaply.

• Keep solutions simple; avoiding complextechnical 'fixes' unless there are noalternatives.

• Try not to condition larger volumes thanabsolutely necessary.

If you have the chance, monitor internal andexternal temperatures and RHs in possiblebuildings, preferably over a full year, see [2,

20]. This will help you to understand howthey actually perform.

1. A Sound ShellExisting buildings need to be carefullychecked for risks of flood, rising damp, leaksfrom roofs or rainwater systems, failure offlat roofs and structural decay. These mustbe eliminated if possible: sometimes by re-pair, sometimes upgrading. Alternatively(see Section]) a robust but imperfect buildingmay sometimes provide shelter and anenvironmental buffer zone to containerswithin: inside these the environment canbecome more stable or better controlled.

2. Low Air InfiltrationTo improve control over temperature, RH orair quality, draughtproofing will frequentlybe a priority. Industrial buildings (even newones, as in the photograph below) are notor-iously leaky - not only at doors and win-

An all-too-typical cross-section of the wall of a modern portal-framed shed, showing faults which signifi-cantly degrade its insulation and airtightness. The insulation stops short of the bottom. The metal Z-spacerand the cill are cold bridges'. Air will also enter directly under and over the cill section, where there are noseals. Air will also infiltrate indirectly via joints in the cladding and the inner liner sheets via the airspace andthe permeable insulation. This will also reduce the insulation's performance.

dows but at joints between panels, at theeaves, where lightweight roofing or claddingmeets the ground or perimeter brick walls,and where brick or block walls abut steel orconcrete columns.As much heat may be lost by unwanted airinfiltration as by conduction through the so-lid elements of the building shell, particu-larly in a well-insulated building. The airwill also carry dirt, spores, insects and pollu-tants. Whatever the building, unwanted ven-tilation will make it difficult to maintainstable RHs and will massively increase therunning costs of humidifiers and dehum-idifiers. Means of reducing air leakage are dis-cussed in sections H and J.

3. Good InsulationMany old buildings are uninsulated, and innewer ones insulation is often poor, in speci-fication or in execution (as in the photo-graph on this page). Ideally all outer sur-faces should be insulated: walls, roofs, andwindows and, if possible, the floor, particu-larly its perimeter.

4. Limiting Heat GainsWindows and rooflights can admit largeamounts of solar radiation, particularly ifsunshine enters directly. This reduces ther-mal stability and may even cause overheat-ing. Internal heat gains from people, lightsand equipment must also be taken into ac-count: a strategy (eg conservation heating)which may work well in a lightly unoccu-pied store may become inappropriate if thestore is lit and occupied for long hours.

5. High Thermal CapacityThermal capacity helps to reduce the buil-ding's rate of response to change: to theweather; occupancy-related gains; or sys-tem failure. It usually resides primarily inmasonry walls (both internal and external),concrete floors, and the contents them-selves. (Note: if these are insulated internally,the temperature-stabilising effect of their masswill be much reduced: external or cavity insula-tion is preferable). Many buildings materialalso have moisture-storage 'sponge' capacitywhich also helps to stabilise moisture levels,as do the stored objects themselves.

13

H Improving the Thermal Performance of The Building Shell

What is a U-Value?The rate of heat transfer through a build-ing element is termed its U-value. mea-sured in Wat ts per square metre perdegree Celsius temperature difference be-tween inside and outside (and expressed asW/m2K).Tbe smaller the U-value, the bet-ter the insulation.

in many stores, extra insulation will be de-sirable. In some - depending on the ob-jects stored and the control strategyadopted - it may not be necessary.

For new industrial buildings which requireheating at a rate of over 50 W/m2 of floorarea, the 1995 Building Regulations ADPart L require the following maximum U-values: (W/m2K)Outside walls, floors and roofs 0.45Walls to unheated spaces 0,6Windows, doors and rooflights 3.3Vehicle access doors 0.7

To meet these normally requires about 75 -100 mm of mineral fibre insulation (or 4 0 -75 mm of foamed plastic, depending ontype) in lightweight walls and roofs, andless in more heavyweight or multi-layeredconstructions. Windows and rooflightsmust be double-glazed and vehicle accessdoors insulated and draughtproofed.

However, many existing buildings are verymuch less well-insulated than this, for in-stance: U-value (W/m2K)225 mm (9 inch) brick wall 2.3275 mm (II inch) brick cavity wall 1.5Ditto with 25 mm cavity insulation 0.7

Uninsulated sheet metal cladding 5.7- with foil-backed plasterboard inside 1.9- plus 25 mm cavity insulation 0.8

Sheet metal cladding with 150 mmlightweight concrete block inside 1.0

Uninsulated sheet metal roof 6.7- foil-backed plasterboard lining 2.0- plus 25 mm insulation LI

Single-glazed windows:Wooden frame typical 4.7Metal frame typical 5.6Rooflights 6.6

These values vary with exposure, from ty-pically 10% more on windswept sites to 10%less in sheltered urban areas. Wi thoutgood design and workmanship, U-values incompleted buildings may not match text-book values. Performance of doubtful insu-lation can be checked by infra-red survey

For more information, see references [5 and 9]and manufacturers* literature.

Upgrading Insulation andAirtightness

Insulation reduces heat transfer between in-side and outside and is usually worth up-grading where practicable, particularly ifthere is none already, or where an elementneeds repair or replacement. However, therecan be pitfalls (see box below), professionaladvice is necessary, and workmanshipneeds constant checking where insulationis built-in.

Floors in existing buildings are seldominsulated. Adding insulation is seldom prac-tical unless replacement is needed for struc-tural reasons or to avoid dampness. Sincemost heat loss occurs at the perimeter, floorinsulation is not statutorily necessary innew buildings more than 15 metres wide (ormore than 10 m wide if over 27 m long).However, in museum stores perimeter insu-lation is always desirable, otherwise it willtend to be colder and damper here. See alsoreference [10].

Lightweight walls and roofs in industrialbuildings often had little or no insulationuntil the 1970s. This made them cold in win-ter, hot in summer, and prone to condensa-tion. Uninsulated cladding and particularlyroofing will usually need upgrading, eitherreplacement by an insulated system, or insu-lating internally. Systems usually have thin

inner linings like plasterboard, but a new in-ner block wall will give better security andthermal stability.

Masonry walls have thermal capacity andsome insulation (see box). Unless clad, orwith cavities suitable for filling, they can bedifficult to insulate cost-effectively Externalinsulation with cladding or rendering (in alight colour to reduce solar gains and radia-tion losses) will improve the appearance of apoor building but be unacceptable for a goodone. Internal insulation will cover the ex-posed thermal mass; and may reduce ther-mal stability particularly where heat gains(eg from occupancy and rooflights) or losses(eg by air infiltration) are large and vary ra-pidly.

If insulation is difficult, approaches whichminimise temperature differences betweeninside and outside, eg dehumidifying, con-servation heating, and/or using buffer zonesmay be useful. See Sections E, J and M.

Roofs generally. Maximum solar gain andheat loss often occurs through roofs. Goodinsulation, a light-coloured finish and noroof lights is usually best. If an otherwisesound roof needs more insulation, aninsulated lining or suspended ceiling maybe suitable if there is sufficient loadbearing

Better insulation can create problems and reveal defects which are less significant in uninsulated struc-tures. For trouble-free performance, careful attention is needed to design and supervision, particularlyin a humidified building. Try to avoid:

• Using combustible insulants.• Obscuring any structure which requires inspection or maintenance by added insulation.• Fire spread in wall and roof cavities.• Damage from water spillage.• Air leakage paths where air, heat and moisture by-pass insulation. These reduce stability, waste

energy and may lead to condensation. Air seals and vapour checks may be required.• 'Cold bridges' where gutters, beams, columns, purlins, fixings, mezzanine supports, etc, by-pass

insulation. Again, condensation can occur here.• Overheating of inadvertently insulated electrical cables.See also reference [15].

14

capacity. Take care to avoid condensation[15], particularly in humidified buildings.Dark finishes will get colder on clear, stillnights (making them more prone to conden-sation), and hotter in the sun.

Flat roofs. Flat roofs should usually beavoided in the main store; there are manypitfalls and the consequences of failure maybe severe. However, there are a few goodones and expert advice should be taken.Sometimes, subject to structural capacity, anew pitched roof constructed above can cre-ate a useful double roof with insulation, ven-tilation and access for maintenance inbetween (Section]).

Traditional roofs. Slate and tile roofs withceilings beneath can perform well after anynecessary repair. Insulation can be addedabove the ceiling, with air/vapour seals androofspace ventilation as necessary. However,where the underside of the covering is im-mediately visible from inside the building,considerable alteration may be necessary toimprove insulation, airtightness and resis-tance to ingress of rain and snow in highwinds.

Windows and rooflights. Rooflights instorage areas may often need to be replacedwith insulated roofing materials, and win-dows removed and their openings filled into match or contrast with the surroundingwalls. In historic and rented buildings, onemay have to retain unwanted windows andclose them up internally: windows may thendeteriorate through condensation and ne-glect. To reduce this risk, the internal clo-sure should be well-insulated, fit tightly,and be removable for maintenance, whilethe space between it and the window shouldhave some ventilation to the outside air.Essential windows should have good seals,

at least double glazing, and UV protectionwhere necessary. Shutters are helpful boththermally and for security. In public areas,staff offices and conservation workshops orlaboratories, a balance must be struck be-tween daylight, view and the related envir-onmental and security problems.

Internal openings. There should be nomore openings in walls and between floorsthan strictly necessary, and no larger thanrequired for daylight, goods, people, and fireescape. If large objects will only be taken oncertain routes, use smaller doors elsewhere.Consider closing redundant doorways, en-closing vertical shafts and stairs betweenfloors, and adding mass and insulation toportions of walls originally thinner thanthe rest.

Air leakage at junctions. Junctions be-tween components are often very leaky, bothto the outside and sometimes betweenrooms. Careful detailing and constructionis necessary to avoid unwanted air infiltra-tion, particularly where tight control is re-quired, see references [5] and [44]. Typicalweak spots include:• At joints between sheets of profiled metal

roofing and cladding, particularly at theeaves and the ridge, even with moderninsulated systems.

• Notoriously at the junction betweenlightweight cladding and foundations orlower masonry walls.

• At junctions between brick and block infilland structural steelwork.

• Missing mortar in joints in brick and blockwalls. If necessary, internal plastering canavoid this.

• Around the outer perimeter of doors andwindows - suitable seals must be specifiedand checked on site.

• Vehicle doors can be particularly leaky. SeeSection].

Air infiltration rates in warehouse buildingsare typically around 1 air change per hour(ac/h) with the doors closed, and can oftenbe halved by simple remedial measures (seediagram). Some leakage paths will be visiblewith the lights off, others may be tracedusing a hand-held smoke puffer. New de-signs and careful refurbishments shouldaim for 0.2 ac/h or less. Carefully controlledventilation may need to be introducedin areas where materials (objects or other-wise) are suspected of off-gassing. Pressuretests can be carried out-by specialist organi-sations to determine air-leakage character-istics.

Smoke puffer in use, revealing air exfiltrationwhere a structural steel column penetrates theinner leaf of an outside wall.

15

Relationships Between Temperature, Relative Humidity and Moisture

Air contains water vapour, up to a maximum (sa-turation) content which rises rapidly with tem-perature. The 'psychrometric chart' (a) belowshows the saturation curve (top), and curves ofconstant RH (expressed as % of saturation) be-neath. For air of a given moisture content (constantvertical distance), RH falls as temperature rises:hence one usually needs stable temperatures ifRH is to be controlled.

The alternative of Conservation Heating(see Section E) manipulates air temperature tocontrol RH. The horizontal line in (a) shows theRH falling from 80% to 60% as the air is heatedfrom 15°C to 20°C

Moisture is constantly exchanged between build-ing, contents and the air. If object and air are onetemperature, the object's moisture content de-

pends primarily on the air's RH (see (b) below). Asthe temperature rises, the RH also needs to in-crease slightly if a constant moisture content is tobe maintained, see [3] and [6]. Hence the elevatedRHs which can occur in UK buildings in summermay be acceptable.

J Buffer Zones, Airlocks, Doors and Containers

Problems with Poor External Walls

Ideally, storage areas for sensitive, inter-mediate or even some robust items shouldnot have external walls, particularly if theseare deficient in performance. Lightweightcladding, for example, offers little physicalsecurity.

Poorly insulated walls reduce thermal stabi-lity and increase the energy and equipmentneeded to control the internal environment.They also increase the risk of dampness andmould in winter (and hence possible damageby fungi, rust, moulds and insects):

• at edges and corners (where heat losses arehigher);

• where material is placed close to them(owing to its insulating effect); and

• where air circulation is poor (reducing thetransport of heat to them).

In such buildings, at the very least avoid pla-cing shelving and objects close to outsidewalls. Better access to the walls also meansthat faults are more likely to be detected andmore easily dealt with.

Planning Buffer Zones

Even in unpromising buildings, it will some-times be possible to devise internal layoutswhich greatly improve passive environmen-tal conditions for storage, reducing the needfor, size of, and energy consumption by buil-ding services equipment. The followingprinciples are applied:

• Try to limit the store area's outside wall byputting circulation routes, offices, etc.around its edge.

• Provide loading areas in which doors can beopened and goods moved (and if necessaryheld for inspection, etc.) without affectingthe store proper.

• Put sensitive objects in separate rooms orcontainers, (with their own environmentalcontrol systems if absolutely necessary) andsurrounded by areas for more robust items,circulation, or people.

• Finally, consider creating micro environmentsfor individual items, for example, by usingsealed boxes [43, 20 chapter 8]. These canalso keep the light out and include physicalprotection, wrappings, and silica gel as abuffer to maintain appropriate humiditylevels.

Caution: Boxes and furniture made out of somehardwoods (particularly oak), a few softwoods(eg douglas fir) and man-made composite boards(eg plywood) may themselves create corrosiveacidic atmospheres.

The Advantages of Internal Rooms

• Better security by extra physical protectionand by permitting devices around theirperimeter (for instance, movement detectorsin corridors and vibration sensors on doorsand walls).

• Isolation from changing weather, possiblecondensation, water ingress, andunscheduled fabric maintenance,

The climate in internal rooms may some-times be stable enough to need no supple-mentary environmental control systems.Where they do, equipment can be lower-powered, more easily controlled, and willuse less energy. Some types of equipmentare outlined in chapters 7 and 8 of reference[20].

Roof Buffer Zones

The roof is often a weak spot. Upstairs roomsand roof voids above can be used to buffersensitive areas. For really secure storage, adouble roof can provide an environmentaland security barrier and a second line of de-fence against water ingress or roof failure.Such roofs can also be inspected and main-tained without intruding upon the storagearea.

The ventilated roof void at Suffolk Record Office,Ipswich. The upper roof provides shade and shelterto a bunded and insulated flat concrete slab.

Appropriate Containers

Containers used in stores include polythenetents, steel tool stores, relocatable buildingmodules, and more conventional structuresin plasterboard and blockwork. All havetheir uses: see the facing page and SectionM. Second-hand transport containers canalso be used, but be sure that insulation isnot damp, decayed or infested.Caution: Heat from occupancy, lights, refriger-ant-based dehumidifiers and even fans maycause insulated and sealed internal rooms andcontainers to overheat, particularly if well-in-sulated or if adjacent rooms are warm. Try tominimise unwanted heat sources and, if neces-sary, consider using low-powered ventilationsystems to remove heat and internally gener-ated pollutants.

Doors for Goods,Vehicles and People

New external doors should be insulated (asrequired for new buildings in 1995 BuildingRegulations [16]) and have multi-point lock-ing. Except to areas used for shelter only, alldoors, including internal doors to stores ofany sensitivity, need good seals. Resourcecentres regularly visited by the public mayneed draught lobbies to main doors.

The light gets under this relatively new (and uninsu-lated) folding door, so the air certainly can!

Most vehicle access doors are draughty anduninsulated, as in the example above, andthreaten environmental stability (and some-times security too) if they open straight intoa store. An interior lobby at the goods en-trance is often essential, with a second setof doors which stay shut until the outer onesare closed. To ensure proper use, the lobbymust be big enough for the objects, people,trolleys or fork lifts required and the doorseasy to operate. Well-fitting fast-acting auto-matic doors are available where there is reg-ular use by fork lifts. Strip curtains scrapethe objects and will only be suitable whereeverything transported is heavy and will besecurely protected and packed.

Insulated and well-sealed loading doors are now

available.

16

1. Buffer Zone Planning At EagleWharf Road

The Museum of London converted a 1960ssteel stockholding warehouse into a storeand resource centre. A steel structure wasbuilt in the southern part of the main sto-rage area to support an intermediate con-crete floor. The two floors were each dividedinto four main areas by concrete block walls,with an access corridor for people and lightobjects to the south. A double-height accesszone to the north admits large objects (vehi-cles and machinery) into the ground floorstores, while fork lift trucks can raise palletsto the first floor.Each area has independently controlled con-servation heating (see Section E) using theoriginal hot water boilers (soon to be re-placed by smaller, more efficient ones). Oneupstairs and three downstairs bays werefitted with new high-level pipe coils. Theremaining bays retained the originalsuspended radiant panels.

On completion, conditions were monitoredand soon found good enough for the morerobust items. However, and as expected, finercontrol was needed for intermediate and sen-sitive items (see Section E for definitions ofitems in italics). A site survey revealed that:• The control and commissioning of the

conservation heating needed attention.• The well-insulated roof needed

draughtproofing, particularly at the eaves,hips and ridge. The uninsulated valleygutters also needed attention.

• Junctions between block walls and steelstructure also needed sealing.

• All the large doors, both for vehicles and thefire shutters to the stores, were uninsulatedand too leaky.

Computer modelling showed that the circu-lation areas worked well as buffer zones, andthat with conservation heating there was noneed to upgrade external wall insulation. Ifthe airtightness of the doors was improved,and the conservation heating was con-trolled to achieve its theoretical perform-ance, then most of the space could also suit

intermediate items, with only small compart-ments required for sensitive items needingcloser control of RH. Residual air infiltration(averaging about 0.2 ac/h) was expected tobe adequate for ventilation needs. The pre-dicted annual energy cost was £2/m2 for theconservation heating, plus a similar amountfor the fine tuning in the compartments, against£24/m2 for full air-conditioning.

Simplified plan of the Eagle Wharf Road ResourceCentre.

2. Conservation Heating and Plas-tic Tents Successfully Used By EnglishHeritage

English Heritage rented a former warehouseto hold the contents of a mansion while itwas restored. The controls for the existingducted warm air system were modified toprovide Conservation Heating. The systemwas fine-tuned to give the necessary controlfor robust and intermediate objects and hasworked well. A relatively high RH of 60-65%was chosen to match conditions in the house

and to limit the upward drift in humid sum-mer weather.The first trace shows wide fluctuations intemperature achieving a much more stableRH in the main store, but with occasionaldips when the wind changes and the moist-ure content of the outside air falls fasterthan the store can cool. The lower traceshows the stabilising effect of the plastictent, both on temperature and particularlyRH: the heat and moisture content of thestored materials were enough to avoid theneed for supplementary humidity controlequipment.

3. An Unheated Store with an Air-Conditioned Plasterboard Container

Bewdley Museum's store is in the middle of arecently completed block of industrial units.Its main, unheated, area contains industrial,household, agricultural and building items.More sensitive items are housed in the low-cost insulated timber studwork container,on the right, which is clad in plasterboardand security-protected. Light items are alsostored on top of it. A small packaged air-con-ditioner keeps the container at 16°C and de-humidifies it if necessary.

Bewdley Museum's store. Insulated studwork con-tainer in the background.

In early 1995, there was a paint spray explo-sion in the unit next door (to the left). Thesolidly constructed party wall substantiallycontained the serious fire that followed.However eventual partial collapse knockedblocks from the party wall on to a few objectsand showered the collection with dust.While the stud work container completelyprotected the sensitive objects, they mightnot have been so lucky had the explosionbeen on the other side. This experiencedraws attention to some of the hazards ofneighbours on industrial sites which needto be considered very seriously when select-ing appropriate buildings.

17

K Building Services 1: Heating and Ventilation

Heating Equipment

The table and diagrams opposite outline keyfeatures of heating equipment often foundin industrial buildings, classified as:A. High temperature radiant units.B. Warm air heater units.C. Ducted warm air systems.D. Hot water systems (with boilers).E. Other electric systems.Note that existing systems will often be un-suitable for museum stores, and frequentlyin poor condition. Remember to look at theboiler room if there is one.

Warm air systems usually recirculate mostof the air, sometimes introducing a small orvariable proportion of outside air, filtered asnecessary. This can help:• Introduce a known quantity of fresh air.• Pressurise the building, so air leakage is out

rather than in, which increases cleanlinessbut can cause interstitial condensationwhere the inside air is humidified.

• Use outside air for cooling as required,particularly at night in summer.

General principles for storageWhere required, heating for stored objectsshould be gentle, continuous (at least duringthe heating season), uniform, and energy-efficient. Aim to minimise risk from fire andflood (see box), and:• Moisture and pollution in combustion gases

from flueless heaters (also known as direct-fired heaters) including oxides of nitrogenand sulphur.

• Unsuitable or variable conditions.• Heating objects too much in hot air streams

from air grilles, radiators and convectors, orby radiation - particularly with hightemperature overhead sources.

• Stratification of warm air at high level,prevalent with warm-air heaters, high-output natural convectors and some radiantsystems. This wastes energy and makesupper shelves too warm.

If stratification is a problem, 'punkah ceilingfans can help to mix the air.

Conflicting comfort requirementsCool winter temperatures, suitable for ob-jects, may cause complaints from visitorsand staff. Try not to provide comfort condi-tions throughout: this is not only expensive,but may incur extra costs of humidificationto counter the consequent drying effect, andincrease the risk of instability if any of thesystems go wrong. Instead consider appro-priate clothing for staff, separate warmrooms to which staff and visitors can retire,and local radiant heaters to improvewarmth in specific places (or possibly under-floor heating panels in well-used areas).

Fuel choiceMains gas, where available, will often be themost convenient and economic heating fuel,and suits a wide range of heating equip-ment. Liquefied petroleum gas (LPG), ismuch more expensive. Solid fuels will sel-dom be appropriate.

Oil, in recent years often cheaper than gas,does not burn as cleanly and has extra sto-rage, handling and maintenance require-ments, so is usually used only where thereis no mains gas. Electricity although expen-sive for heating, is particularly appropriatefor:• Fast-response on-demand local systems for

personal comfort.• Fine control in inner rooms or containers for

sensitive objects.• Off-peak for background and conservation

heating, particularly for small buildings onremote sites and which need relatively littleheating.

Ventilation Systems

In most industrial buildings, even well-sealed ones, natural air infiltration will of-ten provide sufficient fresh air for museumstorage purposes and remove normal levelsof pollutants. Extra ventilation may howeverbe needed for:• Internal rooms and in particular those in

which people congregate, pollutants aregenerated, or in which good conditions forsensitive objects are sought.

• Drying-out the building before and afterhandover, particularly if it is new, if newfloors and walls have been built in concrete

Fire and Flood RisksExtensive assessment of risks is beyond thescope of this guide. in general:• Avoid heaters with integral burners,

particularly radiant & Unflued,• Electric heaters are a fire risk if inadvertently

covered or kicked oven All should be to BritishStandards with BEAB approval, regularlytested. and permanently wired (not plug-in).

• Never use portable paraffin or gasheaters, Do not store paraffin, bottled gasor flammable hazardous chemicals in themain building.

• Keep sensitive items off the floor and donot have pipes above or near them.

• Take care with pipe joint quality, use weldedconnections where possible.

• Specify and lay out pipes to minimise risk offailure through expansion, contraction andimpact damage.

• Avoid automatic refill from the mains as largevolumes of water could flood into an unattendedbuilding.

• Consider low-pressure or low-level alarmsto alert staff to minor leakages before theyget worse.

• Make regular maintenance and safety checks.Abide by COSHH regulations.

• Check all contractors meticulouslyAim to separate hazardous parts from the col-lection, eg with all fuel-burning plant and pipe-work outside the main store; boilers in separateplant rooms; heat transfer in air handling unitswhich if not outside the store ore arranged todrain to outside. Consider gutters under over-head pipes, with water detectors at their lowpoints. See [18, 25 and 33].

and masonry, or if wet objects or materialssuch as pallets have been brought in.

• Removing volatile chemicals introducedduring construction, decoration, and infittings and furnishings, and from storedmaterials which release pollutants badly.

• Removing unwanted heat, particularlyin hot and sunny weather, or in well-insulated stores during periods of intenseoccupation, for example when loading-up.

Useful ventilation systems include:• Low-capacity natural 'trickle' ventilators for

minimum fresh air requirements. It is easierto seal a room or building up tightly and toadjust ventilators as required, than to buildless carefully and to hope things come outright.

• Automatically controlled fans or naturalventilators for more substantial or variableneeds.

• Ducted heating and air conditioningsystems. These can also pressurise thebuilding to reduce air infiltration.

Windows and doors may also be used, butcontrol can be difficult if the site is not regu-larly occupied, security may be compro-mised, and birds and insects may beadmitted unless screens are fitted.

Air must circulate freely. Natural circulationwill often suffice but forced circulation canimprove the uniformity of temperature andRH distribution, and will often be needed inlarge or obstructed spaces, particularlywhere heat sources are localised or wherehumidifiers and dehumidifiers are used.Avoid 'dead spots', for example solid-backedshelves tight from floor to ceiling, with noair spaces above or below. Do not put shelvesand objects tight against outside walls, espe-cially if these are poorly insulated, owing tothe risk of dampness and related decayproblems. (see Section J), and keep objectsand bottom shelves off the floor, particularlynear outside walls.

(Notes to table opposite)Note 1. Unsuitable, except possibly in well-ventilatedloading bays,Note 2. Unsuitable, except possibly for loading bays,carefully defined personnel areas in the main store. andstores for robust objects like industrial machinery.Note 3. Like a light fitting with infra-red lamps. Red glow.Low maintenance. Useful for on-demand comfort heatingpoints in stores and loading bays.Note 4. For safety and economy. consider fitting timersto allow say 30 minutes' operation only.Note 5. Air leaving these heaters can be very hot, whichwill dry any items in the air stream. Take care.Note 6. Stratification (warm air at high level) is very likely,affecting items on upper shelves and mezzanines. Punkahfans may help to avoid this.Note 7 Ducts normally at high level The better systemstend to be more expensive as they need more ductwork,etc, to ensure good air circulation,Note 8. Existing systems may have used process steam ormedium- or high-temperature hot water, This may no long-er be available on site.Note 9. Automatically destratifies. may include inductionnozzles, particularly useful in tall buildings. Flueless, directgas-fired systems unsuitable,Note 10. Take care to avoid overheating items above andnear radiators. Stratification can easily occur if emittersare too hot or concentrated at too few points.Note 11. Economical to run but. expensive to install. Onlyfor background heating unless store is very well insulated.Danger from floor damage and drilled holes.

18

[Type or Equipment DescriptionDetails

A. High Temperature Radiant Heaters

Al. Gas-fired radiant plaque.A2. Gas-fired radiant tube.Flueless versions of AS and A2.A3. Electric quartz lamp heater.A4. Electric bar heater.

A5. Electric radiant strip.

B,Warm Air Unit Heaters

B1. Gas or oil-fired unit heater.

B2. Gas or oil-fired unit heater.Flueless versions of B1 and B2.B3. Unit heater with hot waterheater coil.

C. Ducted Warm Air Systems

C1. Low velocity.C2. Low velocity.C3. High velocity.

D. Hot Water Systems

D1. Radiant strips and panels.D2. Radiators and convectors.D3. Underfloor heating.

E. Other Electric Systems

EL Off-peak electric underfloor.

E2. Off-peak storage radiators.

E3. Off-peak storage warm air

E4. Small electric heater: radiant

Advantages DisadvantagesComments in italics apply to all the items in the group.

Fast responding. Local

Wall mounted or suspended. Fast-responding, compact.Wall mounted or suspended. Fast responding, black heat.Ditto but flue gases are released into the building.Wall mounted or suspended. Very fast response, compact.Wall mounted or suspended. Fast response.

Wall mounted or suspended. Fast response, black heat.

Wall mounted or suspended.

Floor standing with flue.All types.Wall mounted or suspended.

Heat exchanger in AHU.Oil or gas fired units.Various heat sources.

Normally ceiling mounted.Normally at perimeterPipes embedded in concrete.

Cables embedded in concrete.

Heat stored in blocks.

Heat stored in blocks.

, convector, fan convector.

Widespread.

Out of the way.

Fewer needed than Type B1.None for museum stores.Out of the way.Can be useful for loading baysetc.

Can be very good.

Potentially good.No boiler needed.Saves ductwork.

No fire risk in store.

Out of the way.Widely understood system.Uniform, gentle heat.

No other fuel supply needed.

Uniform, gentle heat.

Low capital cost.

Circulates air too.

Useful for small stores.

Fire risk. Some heaters flueless.

Yellow glow, fire risk, flueless.Fire risk. Fan noise, Flue needed.Unsuitable for main storage areas.High fuel cost.High fuel cost.

Bulkier than A3 and A4.

Fire risk. Often noisy.

Difficult to maintain. Flue needed.

Noisy. Poor heat distribution.Combustion gases in room air.Hot water pipes at high level.

Poor systems no better than B.

Boiler required.Less controllable, more fire risk.Can be turbulent at high level.

Can be leakage and flood risk.

Can overheat items at high level.Can get in the way.items need to be kept off floor.

Fuel often much more expensive.

Items need to be kept off floor

Inflexible. Control charge carefully.

More flexible than E3.

Controls may need upgrading.

Comments

items in radiant beam canoverheat

See Note1See Note 2See Note ISee Notes 3 and 4A3 normally moresuitable.A3 normally moresuitable.

See Notes 5 and 6.

Maintenance thus oftenneglected.Stratification likely.Not acceptable-Can share boiler withradiators, etc.

See Note 7.

See Note 8.Type C1 usually preferable.See Note 9.

See also text on boilers

See Note 8.See Note 10.See Note II.

Confirm adequate supply ca-pacity.

Best for backgroundheating.Danger of overheat andfluctuations.Possibly for backgroundheating.Choose robust and safeequipment.

HEATING SYSTEMS COMMONLY FOUND IN INDUSTRIAL BUILDINGS (PLUS OTHERS OF INTEREST)

SEE ALSO REFERENCE [5]

19

L Building Services 2: Control of Internal Conditions

Control Devices

Controls are a complex subject, often takentoo much for granted until the building isoccupied, when it is usually much more dif-ficult to put them right.

Controls need to do four main things:

• Operate systems safely to minimise risks ofaccident, breakdown, fire, etc.

• Provide the necessary control, alarm andmonitoring to suit the stored items.

• Allow systems to operate economically.• Let users know what is happening and

intervene to the extent desirable.

Unfortunately:

• Designers may make false assumptionsabout how the building and its services willbe operated, making controls difficult tounderstand or to use.

• Occupiers often think that the controls theyneed will automatically come with theequipment. Often one will need remoteitems such as humidistats, plus overlaidcontrols to unify all parts of a system withinan overall strategy.

• The need to commission, maintain, checkand re-calibrate controls is often overlooked.

Appropriate solutions will only emerge fromcareful discussions between the occupier,the designer and the supplier. Sensor posi-tions need to be carefully considered. Takenothing for granted.

Air Conditioning

Strictly speaking, an air conditioning sys-tem should be able to:

• introduce outside air;• circulate internal air;• provide filtration to the level required;• control air temperature within a specified

band, by heating and cooling;• provide humidity control within a specified

band, by both humidification anddehumidification.

Colloquially, however, the term is used forsystems which do only some of these things,resulting in misunderstandings and under-or over-specification. For example, buildingoccupants often call any central ducted ven-tilation system air-conditioning, whilemany packaged room 'air-conditioners' pro-vide air circulation, cooling, and rudimen-tary filtration only, and may dehumidifywhen cooling whether you want it or not.Make sure that your advisers know what youwant and that you understand what you arebeing offered. When you visit other buildings ofinterest try to find out exactly what equipmentthey have got, and how it is actually controlled.

A general outline of air-conditioning can befound in reference [36], while [3] gives moreinformation on principles and applications

for museums, including filtration for bothparticulates and chemicals. In most storesin industrial buildings, air-conditioning willbe restricted to packaged units in innerrooms for sensitive items only.

'Close control' units (as often used in compu-ter rooms) provide the full range of tempera-ture and humidity control functions in onepackage. However, since these are relativelyexpensive, often only the components ne-cessary to avoid the worst problems are cho-sen. For example, items which need to bekept cool and dry might have a cooling-onlyroom air-conditioner set to a maximum tem-perature of say 16°C and a dehumidifier setto 40% RH maximum.

If the main store requires some form of airconditioning, a central ducted system willnormally be chosen, incorporating the fea-tures required. Its fans will normally oper-ate continuously and can use a lot ofelectricity in the course of the year. It istherefore important for them and the asso-ciated plant to be efficient and to handle nomore air at a pressure no higher than strictlynecessary.

Boiler plant (where fitted)Museum stores often require heat for longhours but in relatively small quantities,which makes it important that the boilerplant is efficient at a small proportion of thedesign load. 'Condensing' gas and oil boilers(see references [17] and [35]) although rela-tively expensive, should be seriously consid-ered because they are not only highlyefficient but they retain this efficiency overmost of their load range. In multi-boiler in-stallations, boilers should be sequenced, sothat ones not required are not onlyswitched-off but valved-off and can cooldown. At the very least the lead' boiler(which runs for the most time) should becondensing,

Humidity Control

Ideally humidity control should be incorpo-rated in a ducted air system which circulatesthe air uniformly throughout the space andavoids any local dry or damp spots.

HumidificationIf humidifiers are required, and althoughthere are many types to choose from, elec-trode boiler units may often be appropriate,as they produce sterile steam without che-mical or biological contaminants. For finecontrol, variable output units are preferable.Humidifier breakdown can be very dama-ging: add safety humidistats which can shutdown the system and sound the alarm.

DehumidificationExcess moisture can be removed from the airin two main ways:

1. Condensing it on a cooled coil in an air-handling unit (AHU) or a refrigerant-basedpackage dehumidifier. These units do notwork well in unheated stores - their effi-ciency drops in cold air and the coils canfreeze.

The cool dehumidified air will then need re-heating - self-contained units have a sec-ond coil which re-injects the heat extractedplus heat from the compressor, into the leav-ing air stream. The extra heat can be useful,but in well-insulated stores, enclosed rooms,and in summer, the store may get too hot.Remember to provide drains for the conden-sate: it is not convenient or safe to be foreveremptying buckets.

2. Absorbing it into silica gel or a similarinsoluble material, supported on a drumhoneycomb which rotates slowly, carryingit between the store air and a regeneratingwarm air stream. Avoid absorbents such aslithium chloride: these have sometimes beenreleased into the air when the equipmentwent wrong and coated items in the storewith hygroscopic salts.

These are particularly useful for unheatedmuseum stores because they work better atlow temperatures and have less heating ef-fect (though this depends on model). Electricregeneration heating is convenient in smallrooms, but gas is much cheaper and ispreferable for larger units. Remember toprovide ducts to the outside for the regener-ating air.

20

M Case Study: Assessment and Upgrading of Industrial Units

The Choice

Exeter City Museum sought advice underthe Department of Industry's Energy DesignAdvice Scheme (EDAS) on the choice betweentwo portal-framed 'sheds'.

Building A. A recently completed free-standing steel-framed industrial unit withlightweight insulated cladding, 14 m wide,27m long and 5 m to the eaves.

Building B. A 1960s heavyweight concreteindustrial unit in the middle of a terrace ofsimilar units which shared thick blockworkparty walls. This was 45 m long, 18 m wideand 7 m to eaves.

Building A is a typical modern Advance Fac-tory Unit (AFU). Developers and governmentagencies build AFUs speculatively to suit awide range of light industrial, service andwarehousing activities. However, if the te-nant is known before construction (a so-called 'pre-let'), the developer may be pre-pared to change the specification to meettheir requirements, although the externaldimensions, structural system and claddingmaterials will tend to be fixed.

The Stems to be Stored

Many museums seeking storage in indus-trial buildings have a relatively high propor-tion of heavy, bulky and robust items (seeSection E). At Exeter, however, much of thematerial is light and relatively sensitive, in-cluding biological, mineral, textile and eth-nographic collections as well as bulkarchaeology. For reasons of management,environmental stability, security and firesafety, the different collections and materialtypes would need to be kept in separate con-tainers within the main store.

Site inspections ©f Buildings A and B

Although new, Building As thermal charac-teristics were disappointing. Walls and roofhad theoretical U-values of 0.4,5 (see SectionH), but being lightweight they lacked ther-mal stability; they also had 'cold bridges'(see Section G). The doors were uninsulatedand they and the walls were also far fromairtight. Its large rooflight area (12%) ad-mitted excessive amounts of daylight, sun-light and solar heat and significantlyreduced its thermal stability. It was also notbig enough to accommodate everything un-der one roof, even with a mezzanine overmuch of its area. The portal frames wouldalso slightly restrict headroom in the mezza-nine near the eaves.

Building B was less well-insulated, with nowall insulation and a roof U-value of about0.8 W/m2K. Its vehicle doors were even lessairtight and it had a large glazed gable at the

north end. On the other hand, Building Bbenefited in thermal stability from its mas-sive wall construction and by being shel-tered by its neighbours in the terrace, andthis made it thermally more stable thanBuilding A. If the redundant rear (south) ve-hicle door was bricked-up and a new wallbuilt inside to create a loading bay, work-shop and office area at the north end, thenthe building could potentially work well.

Thermal modelling revealed that Building Bwould be better than Building A at stabilis-ing the internal environment (see typicalsummertime temperatures below). However,it had technical problems, in particular trou-blesome valley gutters above the party walls.These had leaked over many years andalthough recently repaired, the walls werestill very damp. The moisture might alsohave caused the concrete structure to decayand the associated steelwork to corrode. Astructural survey was recommended.

Conclusions

With the shortcomings in Building A, a pre-let (also available at the same 1995 rental le-vel of about 4/ft2 per year) was preferred.This could be larger, with better insulation,few rooflights, insulated doors, and atten-tion to detail in design and on site to reduceair infiltration and told bridges'. The wall'sinner leaf could also be of blockwork, im-proving thermal stability.

If Building B proved to be structurallysound, however, then it had advantages:- immediately available- a lower rental level (3/ft2 or less), in spite

of its greater height- a better location- a high floor loading.

Building B could serve effectively as an outershell to protect a two-storey terrace of con-tainers built inside and housing the sensi-tive items: this would assist environmentalcontrol, security and fire protection.

The diagram below shows how effective con-tainers can be in stabilising the environ-ment: suitable insulated blockworkcontainers would be ideal, provided thattime could be allowed for them to dry themout before occupation. If conservation heat-ing were applied to the outer envelope, thenfor many of the containers it was likely thatthe amount of fine-tuning necessary wouldbe small, and could normally be achievedsimply by means of low-powered heatersand/or dehumidifiers.

The principles adopted were, however, ap-plicable to a wide range of buildings. It wastherefore recommended that other suitablebuildings, better located for public access,should be considered before making a finaldecision.

The EDAS study has now been incorporatedinto the Museums Service Storage Plan.

21

N Points to Remember: Four Checklists

These checklists, which are not comprehen-sive, pick up issues which had repeatedlycaused difficulties in projects reviewed whilethe Guide was prepared.

Organisational Checklist

AT INCEPTION• Make sure you have an effective team, with

designated individuals responsible for co-ordination on both the client side and thedesign side, and with the conservator fullyinvolved throughout.

• Visit similar buildings as a team in order toaid decisions and to share ideas.

BRIEFING STAGE• Consult the full range of users.• Decide performance requirements.• Identify containers/equipment needed.• Think hard about future changes, including

changing your mind.

BUILDING SELECTION• Is the location convenient and secure?• Will staff be happy to go there?• Is there enough scope for adaptation and

extension?• Is the rent too high? Check local agents'

knowledge and comparable buildings.• Are there associated commitments?• Will alterations change rent/rate levels?

DESIGN AND CONSTRUCTION

Design stage• Don't leave it all to the design team: review

designs regularly. Check plans, dimensionsand technical proposals.

• Check flows of people and goods.• Review security: reception, guarding

circulation, views, surveillance.• Visitor numbers may grow: is there

sufficient provision?• Prepare lists of critical items (eg sealing

hidden joints) which need to be checkedand 'signed off as built.

Dur ing construction - check:• Junctions: are they properly sealed?• Surfaces: are they smooth and clean?• Openings: are they secure and airtight?• Switches/controls; are they convenient?• Prioritise carefully if budgets are cut.

BEFORE HANDOVER ASK FOR:• Plans and specifications, including services,

structure and drainage, with as-fitted (notdesign) drawings.

• Instructions for all equipment.• Records of tests for all systems.• Addresses of suppliers.• Operating and maintenance instructions.• Briefing in the maintenance and use of the

building and its equipment

Do not accept the building until you are sure youhave got what you asked for and the contractrequired.

Storage Checklist

Don't pay to store air. If possible workout from the objects to be stored.Aisles too wide? Consider mobile rackingor different access equipment.Do you have space for unused furni-ture and containers? Unless they fold ornest, empty containers and pallets take asmuch room as full ones.

MEZZANINES:TAKE CAREBeams too low. Ultimately you are nearlyalways going to want to put mezzanines inany area with enough height. Think care-fully when selecting and planning buildings.Access poor. Provide easy stairs. Considerhinged sections of guard rail with padbolts,for forklift access.Floors don't line up. Have a strategicplan. Where possible adopt a suitable com-mon level.Not strong enough. People will ulti-mately want to use all available flat sur-faces over offices, etc. Make them strongenough and avoid obstructions by electri-cal cables, etc.Not stable enough. Vibrations trans-mitted from walkers and trolleys.

Move-In andOccupancy ChecklistRemember drying-out• This may take months; even with careful

management. Unwanted moisture isparticularly troublesome if the building iscompleted in the autumn or winter.

Plan the moveHave time and facilities been allowed for:• Sorting, cataloguing, decontaminating and

re-packing material as it arrives.• Have you enough racks, pallets, containers

and handling equipment, and space to putthem?

• Avoid multiple handling of items.Document the whole process.

During occupancy• Have a manual for managing the store.• Have one person responsible for the

building who can keep an overview.• Make regular inspections.• Monitor the internal environment [20,

chapter 5]. Consider remote monitoringand alarms if unmanned.

• Keep statistics and records up to date.• Set energy targets and review

consumption regularly [31, 32].• Undertake maintenance and where

possible upgrade as you maintain.

Do you understand the building?• Be briefed by the designers.• Obtain record drawings and operation and

maintenance manuals.• Witness acceptance tests of the services.• Arrange suitable training.

22

Technical Checklist

FLOORSInsufficient loadbearing capacity. Is re-inforcement, consolidation or segregationof heavy items required?Uneven. Consider levelling and consolida-tion, particularly for mobile racking, trol-leys and forklift trucks.Dusty. Often a problem with concrete.Consider tough paints or consolidants, co-loured to check coverage.Damp. Reconstruct.

ROOFS AND WALLSSafe and secure?Condensation and damp. Rising andfrom roofs, valley gutters, downpipes andunsuitable water and heating pipes. Coldbridges and exposed corners.Lightweight construction at low levelvulnerable to cutters and ramraiding.Headroom restrictions. By structure,suspended lights and trunking. Think care-fully when planning.Is the insulation effective? If necessarycheck by infra-red survey.

UNWANTED AIR LEAKAGEConstruction joints. Check for lighttightness and with a smoke puffer. Seal ifyou can. Consider pressure testing.Loading doors. Consider replacement.Usually uninsulated and often very leaky.Old ventilators, etc. Block up.

ROOFLIGHTS AND WINDOWSSafe and secure?Damage by light or solar heat?Block-up or consider blinds or shutters.Avoid condensation if retained.

LOADING BAYSUnlobbied or absent. Will air leakage,exhaust fumes and access of pests be toler-able? Security measures when open?

BUILDING SERVICESPoor light switching. Consider how thestore will be used and how to avoid lightson unnecessarily.Existing heating inappropriate. It oftenwill be. Don't be too optimistic.Inadequate mains supplies. Check avail-ability and capacity.Inadequate drainage.

SECURITY see reference [18].Poor area. Unsafe for staff and visitors?Poor physical security. Too far from po-lice and fire stations?Difficult to supervise access. People, ve-hicles and all entrances need watching. Arethere places to hide?Insufficient segregation of staff andvisitors. Consider relationships early on.Expect visitor numbers to grow over theyears.

P References

1. Storage, UKIC Restoration '91 Conferencepreprint (October, 1991).

2. Museums & Galleries Commission,Managing Your Museum Environment(1994).

3. G. Thomson, The Museum Environment(Butterworth, 1986).

4. Museums & Galleries Commission, Stan-dards in the Museum Care of Collections:Vol 1. Archaeological (1992)Vol 2. Biological (1992)Vol 3. Geological (1993)Vol 4. Larger and Working Objects (1994)Vol 5. Musical Instruments (1995)

5.* Good Practice Guides 61 and 62, EnergyEfficiency in Advanced Factory Units (BREC-SU/EE0' 1993).

6. G. Brundrett, Criteria for Moisture Control(Butterworth, 1990).

7. T. Ambrose and C. Paine, Museum Basics(Routledge/ICOM, 1993).

8. C. Kitching, Archive Buildings in the UK1977—1992 (Royal Commission on HistoricalManuscripts/HMSO, 1993).

9. CIBSE Guide Part A3, Thermal Propertiesof Building Materials (CIBSE, 1986).

10. B. R. Anderson, The U-value of SolidGround Floors with Edge Insulation, BRE In-formation Paper IP 7/93 (1993).

11. J. Ashley-Smith, N. Umney and D. Ford,Let's be Honest - Realistic EnvironmentalParameters for Loaned Objects, IIC OttawaCongress preprints, 28-38 (September,1994).

12. S. Michalski, RH: A Discussion of Correct/Incorrect Values, ICOM Committee for Con-servation, Vol. II, 624-28, (Washington,1993).

13. CIBSE Lighting Guide LG8, Museumsand Art Galleries (1994).

14. CIBSE Lighting Guide LG1, The IndustrialEnvironment (1989).

15. Thermal Insulation: Avoiding Risks, sec-ond edition (HMSO/Building Research Es-tablishment, 1994).

16. The Building Regulations, ApprovedDocument Part L1: Conservation of Fuel andPower, 1995 edition (HMSO, 1994).

17. CIBSE, Applications Manual AM3, Con-densing Boilers (1989).

18. N. Hoare, Security for Museums (Mu-seums Association, 1990).

19. G. D. & B. Lord (eds), Manual of MuseumPlanning (HMSO/Museums Association,1991), especially M. Frost, Preventive Conser-vation.

20. M. Cassar, Environmental ManagementGuidelines for Museums and Galleries (Mu-seums & Galleries Commission in associa-tion with Routledge, 1995).

21. J. M. A. Thompson (ed), Manual of Cura-torship - A Guide to Museum Practice (But-terworth, 1988).

22. P. Tutt and D. Adler, New Metric Hand-book (Butterworth, 1988).

23. S. Keene, Managing Conservation (UK In-stitute for Conservation of Historic and Ar-tistic Works, 1990).

24. G. Matthews, Museums and Art Galleries:A Design and Development Guide (London,1991).

25. F. Howie (ed), Safety in Museums and Gal-leries (Butterworth, 1987).

26. M. Cassar, 'Environmental Strategies forMuseum Collection Storage', SSCR Journal 3(4) 14-17 (1992).

27. E. Leary, 'Standards for Storage in Alu-seums - UK', in reference [1], pp. 17-18.

28.* CEC Thermie Programme Maxibro-chure, Energy-Efficient Lighting in Buildings(BRECSU, 1992).

29.* CEC Thermie Programme Maxibro-chure, Energy-Efficient Lighting in IndustrialBuildings (BRECSU, 1993).

30.* Good Practice Guide 74, Briefing the De-sign Team for Energy Efficiency in New Build-ings (EEO/BRECSU, 1994).

31.* Good Practice Guide 133, Energy Effi-ciency in the Workplace - a Guide for Man-agers and Their Staff, (EEO/BRECSU, 1994).

32.* General Information Report 12, EnergyManagement Guide (EEO/BRECSU, 1993).

33. East Midlands Area Museum Services,Manual of Disaster Prevention (1991).

34. P. Brimblecombe, The Composition ofMuseum Air', Atmospheric Environment 24a,1-9 (1989).

35.* Good Practice Guide 16, Guidance for In-stallers of Condensing Boilers (EEO/BRECSU,1990).

36.* Good Practice Guide 71, Selecting AirConditioning Systems (EEO/BRECSU, 1993).

37. S. Walston and B. Bertram, 'EstimatingSpace for the Storage of Ethnographic Col-lections', Preventive Conservation, 3rd ARA-AFU COLLOQIUM (Paris, 1992).

38. Building Research Establishment, Bet-ter Briefing Means Better Buildings (ReportBR95,1987).

39. T. Padfield and P. Jensen, Low Energy Cli-mate Control in Museum Stores, ConservationDepartment, National Museum of Denmark(1990).

40. Real Estate Norm: Industrial Buildings,REN Foundation, PO Box 1075. Nieuweigien,Netherlands (1993).

41.* Energy Consumption Guide 18, Indus-trial Buildings and Sites (EEO/BRECSU, 1993).

42. M. Cassar, 'Preventive Conservation andBuilding Maintenance', Mus. Mgt and Curator-ship 13 39-47 (1994).

43. M. Cassar and G. Martin, The Environ-mental Performance of Display Cases, Pre-prints of IIC Congress, Ottawa, 171-73(1994).

44. M. D. A. E. S. Perera, C. H. C. Turner andC. R. Scivyer, Minimising Air Infiltration inOffice Buildings (Building Research Estab-lishment, 1994).

45. P. Eley and J. Worthington, Industrial Re-habilitation: The Use of Redundant Buildingsfor Small Enterprises (Architectural Press,1984).

46. D. Erhardt and M. Mecklenburg, RelativeHumidity Re-examined, IIC Ottawa Congresspreprints 32-38 (12-16 September, 1994).

47. Best Practice Programme, Introductionto Energy Efficiency in Factories and Ware-houses (EEO, 1994).* References marked with an asterisk areavailable free of charge from BRECSU, BRE,Garston, Watford WD2 7JR, Telephone:01923 664258.Although some of these publications arespecialised and/or expensive, somebody onyour team could well have the one you wantalready. For example, many conservatorswill have [3], architects [15] [16] and [22]and building services engineers, the CIBSEpublications.

23

Q Sources of Advice and Other Information

British Museum Materials Testing ServiceConservation Research SectionThe British MuseumLondon WC1B 3DGTel: 0171-636-1555

BRE (Building Research Establishment)Bucknalls LaneGarstonWatfordWD2 7JRTel: 01923-894040

BSRIA (Building Services Research andInformation Association)Old Bracknell Lane WestBracknellBerkshire RG12 4AHTel: 01344-426511

CIBSE (Chartered Institution of BuildingServices Engineers)Delta House222 Balham High RoadLondon SW12 9BSTel: 0181-675-5211

CIRIA (Construction Industry Research andInformation Association)6 Storey's GateWestminsterLondon SW1P 3AUTel: 0171-222-8841

EDAS (Energy Design Advice Scheme)The Bartlett Graduate SchoolPhilips HouseUniversity College LondonGower StreetLondon WC1E 6BTTel: 0171-916-3891

University of Ulsterat JordanstownNewtownabbey BT37 0QBNorthern IrelandTel: 01232-365131

Royal Incorporation of Architectsin Scotland15 Rutland Square

Edinburgh EH1 2BEScotlandTel: 0131-2297205

The University of SheffieldPO Box 595Floor 13, The Arts TowerSheffield S10 2UJTel: 0114-2768555

EEO (Energy Efficiency Office)2 Marsham StreetLondon SW1P 3EBTel: 0171-276-3000

Museums & Galleries Commission16 Queen Anne's GateLondon SW1H 9AA

Museum Councils in the United Kingdom

Area Museum Council for the South West(Avon, Cornwall, Devon, Dorset, Glos,Somerset, Wilts, Isles of Scilly)Hestercombe HouseCheddon FitzpaineTaunton TA2 8LQTel: 01823-259696

South Eastern Museums Service(incorporates the London Museums Service;Beds, Berks, Bucks, Cambs, Essex, GreaterLondon, Hants, Herts, Isle of Wight, Kent,Norfolk, Oxon, Suffolk, Surrey, East & WestSussex, Channel Islands)Ferroners HouseBarbicanLondon EC2Y 8AATel: 0171-600-0219

Council of Museums in WalesThe CourtyardLetty StreetCathaysCardiff CF2 4ELTel: 01222-225432

West Midlands Area Museum Service(Hereford & Wales, Shropshire, Staffs,Warwicks)Hanbury RoadStoke PriorBromsgrove B60 4ADTel: 01527-872258

East Midlands Museums Service(Derbys, Leics, Lines, Northants, Notts)Courtyard BuildingsWollaton ParkNottingham NG8 2AETel: 01602-854534

Northern Ireland Museums Council185 Stranmillis RoadBelfast BT9 5DUNorthern IrelandTel: 01232-661023

North West Museums Service(Cheshire, Cumbria, Gr. Manchester, Lanes,Merseyside, Isle of Man)Griffin LodgeCavendish PlaceBlackburn BB2 2PNTel: 01254-670211

Yorkshire and Humbers ide MuseumsCouncil(North, West & South Yorks, Humbs)Farnley HallHall LaneLeeds LS12 5HATel: 0113-2638909

North of England Museums Service(Cleveland, Durham, Northumberland, Tyne& Wear)House of RecoveryBath LaneNewcastle upon Tyne NE4 5SQTel: 0191-2221661

Scottish Museums CouncilCounty House20-22 Torphichen StreetEdinburgh EH3 8JBScotlandTel: 0131-2297465

RIBA (Royal Institute of British Architects)66 Portland PlaceLondon W1N 4ADTel: 0171-580-5533

The Royal Institution of Chartered Surveyors12 Great George StreetLondon SWlP 3ADTel: 0171-222-7000

24

MUSEUM COLLECTIONS IN INDUSTRIAL BUILDINGS

A selection and adaptation guide

Many outstanding museums occupy prime sites in city centres. Museum managements wish tomaximise the potential they have to attract visitors by offering better public facilities. However,space within museum buildings is often in great demand. A recent alternative is to seek accom-modation off-site for reserve collections and other behind-the-scene activities. This provides theopportunity to re-house reserve collections in accessible, environmentally stable, safe and secureconditions.

The use of modern or old warehouses, often located on industrial sites, is attractive because of theperception that they are readily available and cheap to acquire. This may be so, but what does it taketo make them accessible, environmentally stable, safe and secure?

The Museums & Galleries Commission's Museum Collections in Industrial Buildings: A selection andadaptation guide brings together strategic and practical advice to such projects. Using a series of two-page spreads to contain different types of information, the publication is designed as a planning toolboth for museums seeking to develop off-site facilities and building consultants looking for adviceon the housing needs of museum collections.

'The aims and objectives of this document areadmirable. That there is a need for such informa-tion can be confirmed by our experiences in asses-sing potential buildings and developing a brieffor the housing of the RIBAs Special Collections'.

(Dr Frank Duffy, PP RIBA.)

£12

MUSEUMS & GALLERIES COMMISSION16 Queen Anne's Gate, London SW1H 9AA